We (scite.ai) have extracted 918M citation statements (3 full sentences) from 27M full-text articles (more than half are from paywalled articles from indexing agreements).

We've taken this an extra step and have classified the citation statements as providing supporting or contrasting evidence (https://direct.mit.edu/qss/article/doi/10.1162/qss_a_00146/1...)

And, recently, have made these citation statements easily searchable to find expert analyses and opinions on nearly any topic extracted from the literature: https://scite.ai/search/citations