- eBookThe Musical Myths and Facts (Vol. 1&2)Carl Engel
- eBookMusical Myths and Facts, Volume I (of 2)Carl Engel
- eBookMusical InstrumentsCarl Engel
- eBookMusical Myths and Facts (Vol. 1&2)Carl Engel
- eBookMusical Myths and Facts, Volume II (of 2)Carl Engel
- eBookMusical InstrumentsCarl Engel
- eBookMusical InstrumentsCarl Engel