Hang Gliding Flying Skills by Dennis Pagen
Posted: Wed Sep 12, 2018 7:51 pm
Dennis Pagen has written a lot of books.
This is the only one you need.
https://www.amazon.com/gp/offer-listing/0936310014/ref=dp_olp_all_mbc
Hang Gliding Association with both National and Local Forums
https://ushawks.org:443/forum/