* International Hip Dysplasia Institute (IHDI)* Online orthopedic textbook [http://www.wheelessonline.com]* Children's Hospital Central California - Developmental Dysplasia of the Hip (DDH)* United Kingdom Support group for DDH, Clubfoot and other lower limb disorders [http://www.steps-charity.org.uk/links/4-15-developmental_dysplasia_of_the_hip_ddh.php]