Não informado. (1944). Ionospheric data. U.S. Department of Commerce, National Bureau of Standards, Central Radio Propagation Laboratory.
Chicago-viite (17. p.)Não informado. Ionospheric Data. Washington: U.S. Department of Commerce, National Bureau of Standards, Central Radio Propagation Laboratory, 1944.
MLA-viite (8. p.)Não informado. Ionospheric Data. U.S. Department of Commerce, National Bureau of Standards, Central Radio Propagation Laboratory, 1944.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.