J. T. Simatupang, S. E. Sitompul, and H. T. Pakpahan, “Factors Influencing Purchasing Decisions for UD Marroan’s Crispy Peanuts, Siwaluompu Village, Tarutung District, North Tapanuli Regency”, AGRICOLA, vol. 16, no. 3, pp. 289-295, Oct. 2026.