Louie PK, Narain AS, Hijji FY, Yacob A, Yom KH, Phillips FM, Singh K. Radiographic Analysis of Psoas Morphology and its Association With Neurovascular Structures at L4-5 With Reference to Lateral Approaches. Spine (Phila Pa 1976). 2017 Dec 15; 42(24):E1386-E1392.