C#5-D#5. Christlieb, Don. Pictoral Fingerings for Bassoon. Published by author, 1966, p. 29. Timm, Everett LeRoy. The Woodwinds; Performance and Instructional Techniques. Boston: Allyn and Bacon, 1964, p. 178.

 eb-tr Eb c#-tr
x  o  x  | o o x Ab-tr

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