VOACAP FOR SWL : A PROGRAM PREDICTING RADIO WAVE PROPAGATION 3 to 30 MHz
https://medxr.blogspot.com/2025/11/new-voacap-online-tools-for-shortwave.html
In French and other languages
https://www.dxrn.info/voacap-un-outil-puissant-pour-predire-la-propagation-des-ondes-radio/
