12 studies opus 33 for flute solo :
(Book II of the Progress in flute playing) /
Koehler ; [edited by] Wummer.
APA Citation
Köhler, E., Wummer, J. (1957). 12 studies opus 33 for flute solo: (Book II of the Progress in flute playing). New York City: International Music Co..
MLA Citation
Köhler, Ernesto, 1849-1907, and John Wummer. 12 Studies Opus 33 for Flute Solo: (Book II of the Progress In Flute Playing). New York City: International Music Co., 1957.
Warning: These citations may not always be complete (especially for serials).