Sobiczewski, P., and T. Bubán. “The Effect of Regalis® (prohexadione Calcium) on the Reduction of Fire Blight (Erwinia Amylovora) Severity in Apple Trees”. International Journal of Horticultural Science, vol. 10, no. 2, May 2004, pp. 61-66., doi:10.31421/IJHS/10/2/462.