https://www.grammarly.com/ for online check

Grammarly: Grammar Checker and Writing App extension for Chome

Grammarly - Grammar keyboard for mobile phone 

https://www.scribbr.com/

Google Scholar

Looking for an academic article, thesis, or abstract? Google Scholar should be your first stop. Google Scholar helps you find related works, locate full documents at your school library, and access scholarly research.

寻找学术文章、论文或摘要. Google 学术搜索应该是您的第一站。 Google 学术搜索可帮助您查找相关著作、查找学校图书馆中的完整文档以及访问学术研究。

ResearchGate

ResearchGate has been described as social networking for research scientists. But ResearchGate is also a great option to find open-access academic sources. Scholars upload their work to ResearchGate, which makes it available to the public for free.

ResearchGate 被描述为研究科学家的社交网络。 但 ResearchGate 也是寻找开放获取学术资源的绝佳选择。 学者们将他们的工作上传到 ResearchGate，从而免费向公众开放。

Internet Archive Scholar

Internet Archive Scholar (IAS) is a full-text search index that includes over 25 million research articles and other scholarly documents preserved in the Internet Archive. The collection spans from digitized copies of eighteenth-century journals through the latest Open Access conference proceedings and pre-prints crawled from the World Wide Web.

Internet Archive Scholar (IAS) 是一个全文搜索索引，包括 Internet Archive 中保存的超过 2500 万篇研究文章和其他学术文件。 该系列涵盖从 18 世纪期刊的数字化副本到最新的开放获取会议论文集和从万维网上抓取的预印本。