TY  - RPRT
TI  - Harmonic generation in free-electron lasers.
AU  - HP Freund
AU  - CL Chang
AU  - H Bluem
PY  - 1987
DO  - 10.1103/physreva.36.3218
UR  - https://pubmed.ncbi.nlm.nih.gov/9899239/
ID  - 9899239
ER  -