↑ Underwood, Oscar Wilder (1913). "Tariff schedules: Hearings before the Committee on ways and means". Strings for Musical Instruments. m/s. 5691. Dicapai February 27, 2010. [T]here is no such thing as crude catgut or catgut unmanufactured.Catgut is a manufactured article and a finished product; the crude form are the intestines or guts of sheep or other animals. line feed character dalam |quote= di kedudukan 67 (bantuan)
↑ Roenigk, Randall K.; Henry H. Roenigk. Roenigk & Roenigk's dermatologic surgery: principles and practice. m/s. 93. Dicapai February 2010. Catgut sutures are derived from the submucosal layer of the small intestine of sheep and the serosal layer of the small intestine of cattle. Check date values in: |access-date= (bantuan)
