Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation

Search Page

Filters

My Custom Filters

Publication date

Text availability

Article attribute

Article type

Additional filters

Article Language

Species

Sex

Age

Other

Search Results

87,563 results

Filters applied: . Clear all
Results are displayed in a computed author sort order. The Publication Date timeline is not available.
Page 1
[Top level design on clinical research].
Zhao YM, Ding J, Zeng L. Zhao YM, et al. Zhonghua Yi Xue Za Zhi. 2010 Apr 13;90(14):942-6. Zhonghua Yi Xue Za Zhi. 2010. PMID: 20646640 Chinese. No abstract available.
87,563 results
You have reached the last available page of results. Please see the User Guide for more information.