Indian literature in Bollywood

A while ago I was reading this article on Gulshan Nanda - a Hindi writer whose frothy romances were very popular in the 1960's and 70's, and who was responsible for several successfull Hindi movies (Saawan Ki Ghata, Patthar Ke Sanam, Kati Patang, Sharmelee, Jheel Ke Us Paar, Jugnu, etc.). The author of the article claims, among other things, that
a) "good" Hindi literature never made it to Hindi cinema,
b) the task of bringing Hindi literature to movies is beyond the scope of Bollywood directors.

This got me thinking - did serious Hindi literature never make it to Bollywood? Right off the bat I can recall several examples of Indian literary classics that did make it to Bollywood, though were not very popular. Here are the ones I've seen and liked. They're from Hindi literature as well as literature from other Indian languages. Though not large in number, they do refute the author's claims that Bollywood is incapable of making movies based on Indian literature. If any of you know of some other examples, I would love to hear about it.