Books by David S. Hepler:
Books in the extended shelves:
![[X-Info]](https://onlinebooks.library.upenn.edu/infouc.gif)
Hepler, David S. (David Skeen), 1927-: Constant amplitude, variable phase filters (National Aeronautics and Space Administration ;, 1965), also by Lonnie Joe Rogers and Goddard Space Flight Center (page images at HathiTrust)
Find more by David S. Hepler at your library, or elsewhere.