D2-Ab2. Christlieb, Don. Pictoral Fingerings for Bassoon. Published by author, 1966, p. 31. Timm, Everett LeRoy. The Woodwinds; Performance and Instructional Techniques. Boston: Allyn and Bacon, 1964, p. 179.
D2: Ab2: x x x | x x x F x x x | x x x Ab E E D D
Heckel-System (German) Bassoon Trills and Shakes by Note Names