Paymard, J., Nobakht, A., Mazlum, F., Moghaddam, M. (2013). The Effects of Different Levels of Dried Aerial Parts Powder and Extract of Pennyroyal­ (<i>Mentha pulegium</i>) Medicinal Plant on Performance, Egg Quality, Blood Biochemical and Immunity Parameters of Laying Hens. *Iranian Journal of Applied Animal Science*, 3(3), 589-594.