C3. McAuliffe, Joseph. In Apfelstadt, Marc and Klimko, Ronald. Bassoon Performance Practice, Teaching Materials, Techniques and Methods. Idaho: University of Idaho, 1993, p. 64. Add one of the following to stabilize pitch: R. H. G key or F key or Ab key.
C3. Peeples, Georgia. "Playing Pianissimo: Mute Fingerings for the Bassoon."NACWPI Journal 62/2 (Winter 1993-1994): 14. Cooper p. 64 plus low D, C, and B keys, L. H. little finger Db, and low E key.
Db x x x | o o o E B C D
Heckel-system bassoon fingerings by note name