Airflow through helicopter rotors in vertical flight
By: J. Meijer Drees, L. R. Lucassen and W. P. Hendal.
Contributors: Hendal, W. P.; Lucassen, L. R.; National Aeronautical Research Institute (Netherlands)
Series: National Aeronautical Research Institute. Report -- V. 1535
Publisher: National Aeronautical Research Institute
Published: 1949
Place of publication: Amsterdam
Number of pages: 20
Notes: Bibliographical references: p. 18-19.