1. Sky-wave backscatter: A means for observing our environment at great distances;Croft;Rev. Geophys. Space Phys.,1972
2. Croft , T. A. The Fresnel zone near periapsis during deep planetary occultations of spacecraft 1976
3. Croft , T. A. Calculating Fresnel regions in the presence of strong refraction 1977
4. Croft , T. A. Two types of radio occultation Fresnel zones lead to different scintillation profiles 1977