Jones, David R. W.Thomas, Conrad Helmuth2005-07-152005-07-151968Barcode: 82481513http://hdl.handle.net/1880/1878Bibliography: p. 103-107.xi, 111 leaves : ill., map ; 30 cm.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.HD 1795 T4 T4 1968Agriculture - Mexico - Tehuacan Valleymaster thesis10.11575/PRISM/21318HD 1795 T4 T4 1968