Dr. Sighard Hoerner’s Fluid Dynamic Drag and Fluid Dynamic Lift are classic references in aerospace engineering and fluid dynamics. These books are wonderful for rapid design and analysis work; I adore and treasure my copies. I have received multiple requests for information on purchasing. 

As of 2022, the Hoerner family sells the Drag book at: http://hoernerfluiddynamics.com/. You can also reach them via email at: drag@hoernerfluiddynamics.com

The Lift book is unfortunately not available except on the used-market. But, you should still get it.

Please be aware that the books remain under copyright until 2045. These are worth the price to have your own copies.