A. Al-Zubaidy, Adel M., S.Ghafoor, Bakhtiar, AND Rasul, Abdulsalam A.. " The Performance of Two Species of Black Cumin (Nigella sativa L.) and (Nigella arvensis L.) Under Different Sowing Dates in Spring and Autumn at hallabja Governorate /Iraqi Kurdistan Region." Ibn AL- Haitham Journal For Pure and Applied Science [Online], Volume 33 Number 3 (20 July 2020)