From: Appendix E, Quality of the Literature
Evaluation and Treatment of Cryptorchidism [Internet].
Comparative Effectiveness Reviews, No. 88.
Penson DF, Krishnaswami S, Jules A, et al.
Rockville (MD): Agency for Healthcare Research and Quality (US); 2012 Dec.
NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.