Tegnander, Agnar, Ketil Jarl Holen, and Terje Terjesen. 1999. “The Natural History of Hip Abnormalities Detected by Ultrasound in Clinically Normal Newborns: A 6–8 Year Radiographic Follow-up Study of 93 Children”. Acta Orthopaedica 70 (4):335-37. https://doi.org/10.3109/17453679908997820.