Development of Ecom50 and Retention Index Models for Nontargeted Metabolomics: Identification of 1, 3-Dicyclohexylurea in Human Serum by HPLC/Mass Spectrometry. - L. Mark Hall; Lowell H. Hall; Tzipporah M. Kertesz; Dennis W. Hill; Thomas R. Sharp; Edward Z. Oblak; Ying W. Dong; David S. Wishart; Ming-Hui Chen; David F. Grant (J. Chem. Inf. Model., 2012)