Surgical treatment of piles: prospective, randomized study of Parks vs. Milligan-Morgan hemorrhoidectomy. - Hosch,S.B.; Knoefel,W.T.; Pichlmeier,U.; Schulze,V.; Busch,C.; Gawad,K.A.; Borelsch,C.E.; Izbicki,J.R. (Dis colon Rectum, 1998)