1. Aitken GT: Proximal femoral focal deficiency—definition, classification, and management, in: Aitken GT (ed): Proximal Femoral Focal Deficiency. A Congenital Anomaly. National Academy of Sciences, 1969, pp. 1–22.
2. Amstutz HC: Prognosis for growth and development of congenital anomalies of the lower extremities. J Bone Joint Surg Am 49: 1011, 1967.
3. Amstutz HC, Wilson PD Jr: Dysgenesis of the proximal femur (coxa vara) and its surgical management.J Bone Joint Surg Am 44: 1–24, 1962.
4. Bevan-Thomas WH, Millar EA: A review of proximal focal femoral deficiencies. J Bone Joint Surg Am 49: 1376–1388, 1967.
5. Borggreve J: Kniegelenksersatz durch das in der beinlangasachse um 180° gedrehte fussgelenk. Arch Orthop Unfallchir 28: 175–178, 1930.