Most times these books are only free for a day or two, so you have to grab them while you can. Worry about whether you really want to read it later if it seems interesting. And be careful, they can change from free to not free at any time.
I have decided to list books for no more than one day to avoid cluttering up the posts, unless there is some reason I think the book deserves extra attention.I have also decided to consolidate to a single post, instead of sometimes splitting them up by subject matter.
From the top 100 free list
The White Vixen
November 1981. Captain Jo Ann Geary, USAF Special Operations, is on a Chinese island, sent there to rescue a captured British secret agent. An expert linguist and martial artist, the Korean-American officer has volunteered to assist UK Royal Marines in the operation, a decision that will lead to the most dangerous mission of her career.
April 1982. A shadow government in Argentina is pushing the country to capture the Falkland Islands, in order to lure the British fleet into a trap. Once again, MI6 calls upon Geary for help. She is to go undercover deep inside Argentina, to find the man behind the plot, confront a terror thought long dead, and prevent an attack that could touch off World War III.
[#39 - seems pretty far fetched, but has a few good reviews. Might be one to give a chance to.]
I ran across a bunch of these textbooks for free today on the top 100 free list from Boundless. Too many to list separately but they may be of use to some. They appear to only work on apps and not actual Kindles other than Android Kindles like the Fire.