1. Aerodynamic penalties of heavy rain on landing airplanes
2. R.V. Rhode; "Some Effects of Rainfall on Flight of Airplanes and on Instrument Indications,'' NACA Rept. No. 803, 1941.
3. B.L.G. Ljungstroem; "Wind Tunnel Investigation of Hoar Frost on a 2-Dimensional Wing Section With and Without High Lift Devices," Aeronautical Research Institute of Sweden, Report AU-902,1972.