Sadiq, M., Ahmad, M., Gama, E. i Sambo, A. 2024. Morbidity Cost and Willingness to Pay for Healthcare Insurance among Wheat Farmers in Jigawa State of Nigeria. Zeszyty Naukowe SGGW w Warszawie - Problemy Rolnictwa Światowego. 24, 1 (mar. 2024), 4–25. DOI:https://doi.org/10.22630/PRS.2024.24.1.1.