TY  - RPRT
TI  - World helicopter market study
AU  - Cleary, B.
AU  - Pearson, R. W.
AU  - Greenwood, S. W.
AU  - Kaplan, L.
PY  - 1978
UR  - https://ntrs.nasa.gov/citations/19790025923
ID  - 19790025923
ER  -