1. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. I. The external anal sphincter. A triple-loop system. Invest Urol 1975;12:412.
2. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. II. Anatomy of the levator ani muscle with special reference to puborectalis. Invest Urol 1975;13:175.
3. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. III. The longitudinal anal muscle: Anatomy and role in anal sphincter mechanism. Invest Urol 1976;13:271.
4. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. IV. Anatomy of the perianal space. Invest Urol 1976;13:424.
5. Shafik A. A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. V. The rectal neck. Anatomy and function. Chir Gastroenterol (Surg Gastroenterol) 1977;11:319.