Who are the leading advocates, and what are the top publications on broad longtermism?

Last year at EA Global London Benjamin Todd noted that longtermism is by far the most underinvested area in EA, under 1% investment, versus 9% given by EA surveys as optimal level.

I want to expand research within the area but first would like to review who are all the current top advocates and what are the top written pieces or collections of writings on broad longtermism, both as a whole, as well as sub-cause areas within broad longtermism?