Wade Pfau, and if you just google name you should be able find some of his academic work.
Michael H. McClung, his book is on Amazon but you can download the first three chapters from his website at no charge.
Early retirement now is part of the FIRE culture, but it has some really great work that can be applied to normal aged retirees.
Here is Pfau discussing the Trinity Study
I would have expected the practice of a middle class worker bee retiring with 401k/IRA money to be well settled in terms of best practices. But far from it.
Best of luck.