For radio amateurs interested in studying HF Radio Wave Propagation,
there is a new free online course that offers a completion certificate for those who successfully complete the final exam online.
New Radio Wave Propagation Course
https://www.meted.ucar.edu/training_module.php?id=1394
There is another free course on Electro-Optic wave propagation:
Introduction to Electromagnetic and Electro-Optic Propagation
https://www.meted.ucar.edu/training_module.php?id=1087
Basically, the formats for these courses are multimedia online presentations with an extra text format for those so inclined not to use the bells and whistles. There is also the ability to download the entire course and take it at home. I was able to place a few courses on my own CD and used an .html page to link to them. Both of these courses can be downloaded and studied, but you must take the completion exam online. Website registration is required at UCAR.edu to track progress, complete surveys and obtain a completion certificate from the website. Speaking of online surveys, I normally find my course completion certificates for download after completing a course survey, but there may be an email option for completion documentation.