1. Private communication with Christian Guertin, Vermont Photonics
2. Parks, R. E., “What is a PSM?”, https://optiper.com/multimedia/what_is_a_psm.mp4
3. Private communication with Joe Gleason, Baltec Div. of Micro Surface Engr., Inc.
4. Prism Alignment using a Point Source Microscope;Parks,2017
5. The autostigmatic microscope