The articles in these encyclopedias, written by experts in the their respective disciplines, can be excellent sources for background information, providing good overviews of science and engineering topics, with bibliographies to key research articles.
Some of these sources are updated periodically with new and/or updated articles, and others have not been updated since their initial publication. You should always check the date of the encyclopedia entry. Was it published in the last year, or is it 5-10 years old? You can also check the sources that the authors cited to gauge the age of the article.
Multidisciplinary ebook and journal publisher with an extensive collection of encyclopedias and handbooks, particularly for science and engineering disciplines. You can search across the collection and limit results to Reference Work Entries, or start by browsing a subject and then select Reference Works.