From the Bassoon-Family Fingering Companion by Terry B. Ewell - Swanson, Robert. "Pictorial Bassoon Fingerings." Woodwind Magazine 4/1 (September 1951): 9. - Wilson, George H. "Bassoon Intonation: No Mystery!" The Instrumentalist 18/7 (February 1964): 66. Reprinted in Woodwind Anthology (Evanston: The Instrumentalist Company, 1976), p. 589.