A single PMID can also be included in templates such as the Citation Style 1 series by means of the |pmid= parameter. Integer values starting at 1 are allowed.
The linking is done internally to the template using a module or a subtemplate. The "PMID" string links to the article "PubMed", and the PMID number links to the PubMed article with that number.
Koprowski, H.; Wiktor, T. J.; Kaplan, M. M. (1960-04-28). "Enhancement of rabies virus infection by lymphocytic choriomeningitis virus". Virology. 28 (4): 754–756. PMID4957203.
Biblio.php, an extension of MediaWiki, the wiki software used here at Wikipedia. It provides a bibliography management system for wikis and supports direct PMID-based referencing