TY  - BOOK
AU  - O'Bryan, Thomas C.
TI  - An investigation of effect of downwash from a vtol aircraft  and helicopter in the ground environment [NASA TN D-977]
PY  - 1961///
CY  - Washington, D.C.
PB  - Nasa
KW  - Investigation
KW  - Aircraft
N1  - Bound With Nasa Tn D-971-976,978-980; Technical Note D-977
ER  -