@article{CaP1976a,
vgclass = {refpap},
vgproject = {invariance},
author = {D. Casasent and D. Psaltis},
title = {Position, rotation, and scale invariant optical correlation},
journal = {Applied Optics},
volume = {15},
number = {7},
pages = {1795--1799},
month = {July},
year = {1976},
}