Ecosyste.ms: Packages

An open API service providing package, version and dependency metadata of many open source software ecosystems and registries.

rubygems.org "crossref" keyword

textminer 0.1.5
Search Crossref's search API for full text content, and get full text content.
2 versions - Latest release: over 8 years ago - 1 dependent repositories - 5.08 thousand downloads total - 4 stars on GitHub - 1 maintainer
ref2bibtex 0.3.0
Ok, maybe a bit more, you can pass a DOI and get the bibtex string back too.
10 versions - Latest release: over 5 years ago - 1 dependent repositories - 23 thousand downloads total - 0 stars on GitHub - 1 maintainer