2Christopher D. Williams,Joel Stengel,Michael I. Asike,Dawn M. Torres,Janet Shaw,Maricela Contreras,Cristy L. Landt,Stephen A. Harrison.Prevalence of Nonalcoholic Fatty Liver Disease and Nonalcoholic Steatohepatitis Among a Largely Middle-Aged Population Utilizing Ultrasound and Liver Biopsy: A Prospective Study[J]. Gastroenterology . 2011 (1)