TY  - RPRT
TI  - A second order approximation in the Doppler equation.
AU  - P N Wells
AU  - N D Luckman
AU  - R Skidmore
PY  - 1989
DO  - 10.1016/0301-5629(89)90135-x
UR  - https://pubmed.ncbi.nlm.nih.gov/2922884/
ID  - 2922884
ER  -