1. The os trigonum;McDougall;J Bone Jt Surg Br Vol,1955
2. A hitherto undescribed fracture of the astralagus;Shepherd;J Anat Physiol,1882
3. Ossicle occasionally found on the posterior border of the astragalus;Bennett;J Anat Physiol,1886
4. Rupture of the posterior talotibial ligament with the avulsion of a bone fragment from the talus;Cedell;Acta Orthop Scand,1974
5. Isolated fracture of the posterior process of the talus;Borsay;Z Orthop Ihre Grenzgeb,1952