Ferguson, CW, and DA Graybill. 1985. ?Dendrochronology Of Bristlecone Pine?. Tucson: Laboratory of Tree-Ring Research.

Graybill, DA. 1985. ?Western U.s. Tree-Ring Index Chronology Data For Detection Of Arboreal Response To Increasing Carbon Dioxide?. Tucson: Laboratory of Tree-Ring Research.

Ferguson, CW, and DA Graybill. 1984. ?Dendrochronology Of Bristlecone Pine?. Tucson: Laboratory of Tree-Ring Research.