https://pmc.ncbi.nlm.nih.gov/search/citmatch/
PMC Citation Search
citation searchpmc
https://forums.zotero.org/discussion/128386/feature-request-for-ms-word-plugin-copy-selected-text-to-the-add-citation-search-box
Feature Request for MS Word Plugin: Copy Selected Text to the Add Citation Search Box - Zotero...
Zotero is a free, easy-to-use tool to help you collect, organize, annotate, cite, and share research.
feature requestms wordto thecitation searchplugin
https://reviewers.addons.thunderbird.net/en-us/seamonkey/addon/lexisnexis-citation-search/reviews/
LexisNexis Citation Search :: Reviews :: Add-ons for SeaMonkey
citation searchadd onslexisnexisreviewsseamonkey
https://florida.plantatlas.usf.edu/citation/search
Citation Search / Plant Atlas
citation searchplantatlas
https://www.library.wisc.edu/citation-search/
Citation Search | UW-Madison Libraries
citation searchuw madisonlibraries