Rickards, K. J., Page, C. P., Lees, P., & Cunningham, F. M. Differential inhibition of equine neutrophil function by phosphodiesterase inhibitors. JOURNAL OF VETERINARY PHARMACOLOGY AND THERAPEUTICS, 24(4), 275-281. https://doi.org/10.1046/j.1365-2885.2001.00344.x