Okpara D, Ojikpong T, Udo A. The effect of planting dates on seven varieties of soybean Umudike agroecosystems of South Eastern Nigeria. naj [Internet]. 2009 Feb. 25 [cited 2026 Aug. 4];36(1):124-33. Available from: https://www.ajol.info/index.php/naj/article/view/3214