From the Bassoon-Family Fingering Companion by Terry B. Ewell - Cooper, L. Hugh. "Bassoon Clinic Series, Part Four," Etude: the Music Magazine 47/6 (June 1949): 356. Corey, Gerald E. "How to Improve Your Tuning on the Bassoon." The Journal of the International Double Reed Society 8 (1980): 32. Polonchak, Richard M. "What Directors Should Know about Bassoonists in the Band." The Instrumentalist 30/9 (April 1976): 26. Cooper p. 203.