From the Bassoon-Family Fingering Companion by Terry B. Ewell - Cooper, L. Hugh. The Double Reed 2/3 (December 1979): 17. de Gomar, Juan. In Apfelstadt, Marc and Klimko, Ronald. Bassoon Performance Practice, Teaching Materials, Techniques and Methods. Idaho: University of Idaho, 1993, p. 55. Peeples, Georgia. "Playing Pianissimo: Mute Fingerings for the Bassoon." NACWPI Journal 62/2 (Winter 1993-1994): 14. Steinmetz, John. In Klimko, Ronald. Bassoon Performance Practices and Teaching in the United States and Canada. Idaho: University of Idaho, 1974, p. 69. Whitehead, Charles. In Apfelstadt, Marc and Klimko, Ronald. Bassoon Performance Practice, Teaching Materials, Techniques and Methods. Idaho: University of Idaho, 1993, p. 57. For pianissimo same as Cooper p. 30.