Cobban W.A. The Upper Cretaceous dimorphic pachydiscid ammonite Menuites in the western interior of the United States / W. A. Cobban, W. J. Kennedy, 1993. - III,14 p. p. - Текст : непосредственный.
Marasinghe M.G. SAS for data analysis : intermediate statistical methods / M. G. Marasinghe, W. J. Kennedy, 2008 r=on-line. - Текст : электронный.
Cobban W.A. ammonite Metengonoceras Hyatt, 1903, from the Mowry Shale(Cretaceous) of Montana and Wyoming / W.A.Cobban,W.J.Kennedy, 1989. - 11 p. - Текст : непосредственный.