Generally a person posts a link to the entire written work, excerpting in context.
Where such a link to a complete work is available, yes. Otherwise, no. When I have quoted from J. William Schopf's Cradle of Life I have fat-fingered long passages in myself as needed and simply cited the book. Ditto with Feynmann's Lectures and some other works.
Your claim is uttely incredible and you need to back it up with something.