1. Berens D. L.: Hips. In: Radiological aspects of rheumatoid arthritis. International Congress Series No. 61, p. 307. Excerpta Medica Foundation, Amsterdam 1963.
2. A Roentgenographic Study of Transitory Synovitis of the Hip Joint
3. Fischer F. K.: Joint injuries — Arthrography. In: Roentgen diagnosis. Volume 2, p. 1218. Edited by Schinz H. R., Baensch W. E., Friedl E., Uehlinger E. Grune and Stratton, New York 1952.