C#4-D4. Christlieb, Don. Pictoral Fingerings for Bassoon. Published by author, 1966, p. 25.

x x tr | o x x F
   c#-tr

C#4-D4. Ewell, Terry B. (28 April 1995). Source unknown.

x x tr | x o x 
            F#
Bb

C#4-D4. Timm, Everett LeRoy. The Woodwinds; Performance and Instructional Techniques. Boston: Allyn and Bacon, 1964, p. 174.

x x tr | o o x F

x x x | x x x F-tr
   c#

x x x | x x x
           F#-tr

x x o | tr o o

               F#
x x tr | o x x (F)

        c#
x x tr | x o o
        Bb

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