He also wrote on technical writing, electronics testing and oscilloscopes, impedance, oscillators, and hobbyist electronics projects, and authored an elementary calculus textbook.
This high quality compared to other consumer audio recording formats such as compact cassette attracted the attention of amateur and hobbyist recording artists.
Taxidermists may practice professionally for museums or as businesses catering to hunters and fishermen, or as amateurs, such as hobbyists, hunters, and fishermen.