Ruža, A., Kreita, D., Krotovs, M., Maļecka, S., & Stramkale, V. (2006). Nitrogen Fertilizer Use Efficiency in Winter Wheat Trials. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, 1, 232-237. https://doi.org/10.17770/etr2003vol1.2011