May we suggest the following:
Airborne Topographic Lidar Manual by Michael Renslow, Editor
https://eserv.asprs.org/web/staticcontent/staticpages/4587.htm
Topographic Laser Ranging & Scanning Principles & Process by Jie Shan and Charles Toth
https://eserv.asprs.org/web/staticcontent/staticpages/4583.htm
Digital Elevation Model Technologies & Applications, 2nd Ed. by David F. Maune, Editor
https://eserv.asprs.org/web/staticcontent/staticpages/1069.htm