TY  - RPRT
TI  - Higher-order extrema in two-dimensional wave fields.
AU  - I Freund
AU  - A Belenkiy
PY  - 2000
DO  - 10.1364/josaa.17.000434
UR  - https://pubmed.ncbi.nlm.nih.gov/10708023/
ID  - 10708023
ER  -