question about 2 books on improvisation

[youjean88]

i wanted to know if anybody on this website has read these books

https://www.amazon.com/Improvisation-Systematic-Approach-Classically-Trained/dp/0739043781/ref=sr_1_4?ie=UTF8&s=books&qid=1249974254&sr=8-4

https://www.amazon.com/Piano-Improvisation-Handbook-Carl-Humphries/dp/0879309776/ref=sr_1_1?ie=UTF8&s=books&qid=1249974254&sr=8-1

and to those who have, would you recommend these books? lastly, would you say it is necessary or advantageous to buy both? im asking because there arent any book stores near me that have these books in stock so i cant check them out myself

thank you for your time

ps- i dont think posting these links are illegal because im not really advertising?