Doss, Mildred A. <br/><br/>
Index-catalogue of medical and veterinary zoology. Special Publication. No 3, Ticks and tickborne diseases. I. Genera and Species of Ticks. Part 3. Genera O-X / 
Mildred A. Doss; Marion M. Farr; Katherine F. Roach; George Anastos; US Department of Agriculture. 
 - Special Publication. No 3, Ticks and tickborne diseases. I. Genera and Species of Ticks. Part 3. Genera O-X 
 - Washington :   U.S. Government printing Office,   1974.