If you like Mary Ellen Mark or if you would just like an insightful peek into her photo ethos, I highly recommend this small book that is packed with photos and her commentary on how she approached subjects and why she chose to make photos in her signature style.
https://www.amazon.com/Mary-Ellen-Mark-Portrait-Moment/dp/1597113166" Mary Ellen Mark- The Portrait and the Moment: The Photography Workshop Series.
It's a quick read, and a book that I feel will be reread and perused for many years.