Grahn, B. H., Szentimrey, D., Pharr, J. W., Farrow, C. S., & Fowler, D. (1995). Ocular and orbital porcupine quills in the dog: A review and case series.

Grahn, B H., D. Szentimrey, J W. Pharr, C S. Farrow, and D. Fowler. Ocular and Orbital Porcupine Quills in the Dog: A Review and Case Series. 1995.

Grahn, B H., et al. Ocular and Orbital Porcupine Quills in the Dog: A Review and Case Series. 1995.