However, the development of science and technology and the increasingly diverse needs of readers are requiring the breakthrough changes in management and operation of libraries, with the acceleration of digitisation becoming a top important solution.

Previously, the library was simply a place to store books, newspapers, magazines and readers could only access this source of documents through librarians. Services at the library were also quite simple, such as reading right on the spot, borrowing books and copying documents.

However, with the strong development of technology, the libraries have been developed under the trend of digitisation to become information centres, learning resource centres, scientific research support centres and community cultural centres in many countries. They will possess modern facilities capable of meeting the increasingly diverse needs of different users. Notably, many libraries have become symbols of architecture, education and culture of a country.

It could not deny the efforts of Vietnam’s library industry in self-renewal and capacity improvement to meet the diverse needs of readers in recent years. That was the basis for the increase of the number of library users from 15% to 20% per year, the average number of books and newspapers from 35% to 45% per year.

Libraries have also been gradually modernised. The models of electronic and digital libraries have been formed such as the National Library, the library of Ton Duc Thang University in Ho Chi Minh City and S Hub e-library in the campus of the Ho Chi Minh City General Science Library.

However, to meet the demand and requirements for knowledge, library activities should create a stronger transformation because the challenges posed in the era of technology boom are not small, particularly as readers can access sources of documents, books, newspapers and information via the internet.

The audio book market has also been developed diversely, bringing many benefits to readers. According to Vu Duong Thuy Nga, Director of Library Department under the Ministry of Culture, Sports and Tourism, with the strong development of science and technology today, if libraries do not enter the "game" of digitisation, they will gradually be replaced by other sources of knowledge.

Since 1991, the US Library of Congress has been using new technological advances and the internet to connect with educational institutions across the country. By the end of November 2005, as the world’s largest library, it used digital technology to store books and other materials from all cultures of mankind and announced the project to establish the World Digital Library.

In Finland, readers to the Oodi Library – a new of this kind in Helsinki city can access nearly 3-4 million book categories with just one click thanks to the support from a group of robots sorting books and online services.

The digitisation of documents at libraries not only helps preserve and maintain the life of archived documents more convenient and longer but also attract more users of this source as well as contributing to bringing great benefits and facilitating readers in sharing the information resources of this library to other libraries.

The development of digital libraries still faces many difficulties. In fact, at present, digital libraries are only popular in a few big cities or universities. Meanwhile, libraries in localities have not yet met the demand for human resources, infrastructure, financial capacity and technologies to realise digitisation.

Currently, in Vietnam, there are about 20% of public libraries that do not have digital documents. In addition, there is no clear regulations on the legal rights in digitising documents and providing documents to readers.

Another problem is the lack of linkage and coordination among libraries, leading to the situation of overlapping sources of documents. Several libraries have even spent a lot of money on modernisation projects but only bought modern equipment and then leave it unusable. The human factor is also very important. However, the reality showed a crisis of lack of human resources for the development of digital libraries.

To remove difficulties and speed up digitisation, the library sector needs to determine that document digitisation is a necessary job that should be maintained regularly. Accordingly, the implementation process should be selected in accordance with the actual situation as well as the potential of investment and digitisation for the old documents with high risk of damage, the precious and unique documents and those that are of great interest to many readers.

One of the new points of the 2019 Library Law is the enhancement of linkages among libraries inn adding, purchasing, collecting, sharing and using information resources. This will be the basis for building and developing a shared digital library system that connects all big data digital libraries, towards creating a unified digital library knowledge portal.

Thanks to that, readers can easily access and use them on computers and mobile devices, contributing to meeting the needs of readers as well as promoting reading culture and researching, training and creative activities.

Several libraries have cooperated with publishers to share digitised documents as the publishing houses have actively digitised printed books to serve readers using digital devices.

In addition, according to the experience of many countries around the world, the digitisation of documents is often assigned to one focal point. This focal point will receive the fund directly from the State, different individuals and organisations and then conduct coordination activities for activities.

Deputy Director of the National Library of Vietnam Nguyen Xuan Dung said that this approach will not only avoid the overlapping among sources of documents but also standardises the criteria for document digitisation. Moreover, it is essential to renew and improve the quality of human resources training for library industry under the international standardisation.

The fourth industrial revolution 4.0 will continue to mark technological innovations and inventions. This is both an opportunity and a challenge for the library system of Vietnam, requiring constant efforts in updating new trends, digitising documents, and modernising operation methods to improve their operation. The development of digital libraries is not only meeting the general trend of the world but also the requirement of the library industry itself in order to help this cultural institution develop sustainably towards ensuring its function as a source providing basic knowledge, serving the needs of many contemporary readers and preserving documents for future generations.