Creighton, W. S.; Gregg, R. E. 1955. New and little-known species of Pheidole (Hymenoptera: Formicidae) from the southwestern United States and northern Mexico. University of Colorado Studies. Series in Biology 3:1-46.
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Browne, J. T.; Gregg, R. E. 1969. A study of the ecological distribution of ants in Gregory Canyon, Boulder, Colorado. University of Colorado Studies. Series in Biology 30:1-48.
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