Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Author co-authorship map. Authors with at least four articles were included (n = 127 out of 1190). Connectors indicate co-authorships. Circle sizes were weighted by the number of publications included in the systematic review. Five clusters were found, and are characterised by different colours. Metadata is available in Table S6.
