The need for routine pre-operative coagulation screening tests prothrombin time PT/partial thromboplastin time PTT) for healthy children undergoing elective tonsillectomy and/or adenoidectomy. - Asaf,T.; Reuveni,H.; Yermiahu,T.; Leiberman,A.; Gurman,G.; Porat,A.; Schlaeffer,P.; Shifra,S.; Kapelushnik,J. (Int J Pediatr Otorhinolaryngol, 2001)