学习网站目录
学习网站目录
比菲尔德学术搜索引擎
超过3.4亿件科学文献来自超过11000免费来源。BASE是世界性大型搜搜引擎，存储来自互联网上免费的开放获取科学文献。BASE is one of the world\'s most voluminous search engines especially for academic web resources. BASE provides more than 340 million documents from more than 11,000 content providers. You can access the full texts of about 60% of the indexed documents for free (Open Access). BASE is operated by Bielefeld University Library.
点击进入 - 2023-11-03 - 收藏
PDF SEARCH ENGINE - PDF,DOC,PPT,Ebook search ENGINE
FREE PDF SEARCH ENGINE. support all pdf,DOC,PPT,Ebook! free pdf download. You can search all kind of documents!
点击进入 - 2023-11-02 - 收藏
chemBlink官网
chemBlink provides a free database of chemicals from around the World, searchable for product identifications, CAS numbers, SDS, formulas, suppliers and more. Contact us today.
点击进入 - 2023-11-02 - 收藏
Find Articles官网
Find Articles论文搜索网提供多种顶极刊物的上百万篇论文，涵盖艺术与娱乐、汽车、商业与经融、计算机与技术、健康与健身、新闻与社会、科学教育、体育等各个方面的内容。
点击进入 - 2023-11-02 - 收藏
Book Gold Mine
Book Gold Mine可免费提供大量优质的电子书，演讲稿，笔记和其他类型的文档。提供的类别有很多，比如生物学、商业、计算机科学、数学和物理学等，如果您需要以上类似的PDF文档，这是一个很有用的PDF搜索引擎。Free e-books, lectures, notes and other documents in various subjects
点击进入 - 2023-11-02 - 收藏
SCIRP Open Access
Scientific Research Publishing is an academic publisher with more than 200 open access journal in the areas of science, technology and medicine. It also publishes academic books and conference proceedings.
点击进入 - 2023-11-02 - 收藏