Shukri, Hussein Mahmood. “Effect of Diammonium Phosphate (DAP) Fertilization on Growth of Sage Plant (Salvia Officinalis L.) and Concentration of Volatile Oil”. Journal of Biotechnology Research Center, vol. 10, no. 1, Jan. 2016, pp. 31-36, doi:10.24126/jobrc.2016.10.1.456.