For more detailed information on My Lai itself, and the grim actions of Charlie Company on the ground, I recommend starting with the original "Four Hours in My Lai" book that followed the documentary. It remains an important, but harrowing read.
There is also now, finally, a biography of Thompson that is worth a read too, by Trent Angers. /END https://www.amazon.co.uk/Forgotten-Hero-My-Lai-Thompson/dp/0925417904/ref=sr_1_1?crid=23RE1VVPBYKYY&keywords=the+forgotten+hero+of+my+lai&qid=1658479261&sprefix=the+forgotten+hero+of+my+lai%2Caps%2C54&sr=8-1