TY  - RPRT
TI  - Phase integral theory, coupled wave equations, and mode conversion.
AU  - Robert G. Littlejohn
AU  - William G. Flynn
PY  - 1992
DO  - 10.1063/1.165918
UR  - https://pubmed.ncbi.nlm.nih.gov/12779962/
ID  - 12779962
ER  -