Open Access Database: Some academic journals and academic institutions provide online open access databases, which allow you to obtain a large number of academic resources such as academic papers, journal articles, books and reports for free. Some popular open access databases include arXiv, DOAJ and open access library.
Academic search engines: Some academic search engines, such as Google Academic, Bing and Scopus, can help you find relevant academic resources. These search engines can search academic papers, periodical articles, patents, technical reports and other academic resources. Many academic resources are available for free.
Open Access Journals: Some academic journals offer online open access versions, allowing you to get all articles and contents for free. Some famous open access journals include PLOS No.1, BMC series journals and PLoS series journals.
Online libraries: Some online libraries provide free academic resources, such as Internet archives, world public libraries and public digital libraries. These online libraries provide various types of academic resources.
The importance of learning
Learning enables people to have new understanding and new ideas when dealing with things. Learning enables people to master new means and methods to solve problems. Learning enables people to walk out of the small world with vested interests and move towards an enlightened and harmonious world. You should have a basic learning ability, including the ability to learn extensively, the ability to internalize and reconstruct knowledge reserves, and the ability to collect and process information.
Learning should be persistent, never too old to learn, be good at learning from other people's ideas and learn from others. Learning is a process, and persistence can realize one's own value.