Most of the modern texts are commentaries on the classical texts. And here Thrangu Rinpoche is most prolific. But if you want to study mahamudra, you're far better off getting instructions in person from a teacher, though I wouldn't discourage reading texts as well.
Imagine a man who stands before a mirror; a stone strikes it, and it falls to ruin all in an instant. And the man learns that he is himself, and not the mirrored man he had believed himself to be.
-- Gene Wolfe