DC Underwood et al. Comparison of phosphodiesterase III, IV and dual III/IV inhibitors on bronchospasm and pulmonary eosinophil influx in guinea pigs. J. Pharmacol. Exp. Ther. 1994, 270, 250.
Chemical Name: 6-(4-Difluoromethoxy-3-methoxy-phenyl)-2H-pyridazin-3-one