Back before every translator worth his salt had an always-on, high-speed Internet connection, we had to be more self-reliant in the way of reference sources. So we bought dictionaries. Lots of dictionaries. When I lived in Japan, I’d stop in Jimbocho at least once a month. There was a used bookstore that specialized in technical and scientific books, and I’d buy dictionaries there on the off chance that someday I would translate something relevant.