Nelson, Eldon C.Ahern, Kevin Gene2015-08-272015-08-271981-05-01http://hdl.handle.net/20.500.14446/16680application/pdfCopyright is held by the author who has granted the Oklahoma State University Library the non-exclusive right to share this material in its institutional repository. Contact Digital Library Services at lib-dls@okstate.edu or 405-744-9161 for the permission policy on the use, reproduction or distribution of this material.text