Bb3-Db4. Reid, John W. The Double Reed 4/3 (December 1981): 2.

x x tr | x tr o
        Bb 

Bb3-Db4. Wangler, Steven. In Apfelstadt, Marc and Klimko, Ronald. Bassoon Performance Practice, Teaching Materials, Techniques and Methods. Idaho: University of Idaho, 1993, p. 73. Trill L. H. C hole and R. H. A hole together.

x x tr | x tr o
        Bb

Heckel-System (German) Bassoon Trills and Shakes by Note Names