Assuming you have legally purchased the print version and have created a personal backup digital copy (or you are in a jurisdiction where a library digitized a 1970s out-of-print edition), here is how to optimize the for study.
If you are serious about Latin, the Castiglioni-Mariotti is non-negotiable. Whether you save for the physical tome, convince your library to buy a digital license, or (with caution) find a scanned PDF, make sure this masterpiece of Italian philology is on your virtual or physical bookshelf. It is not just a dictionary; it is the key to the mind of Rome. Dizionario Latino Castiglioni Mariotti.pdf
: A separate booklet often included in the package that teaches students how to navigate the complex entries and interpret abbreviations. Assuming you have legally purchased the print version