Kuswardani, Retna Astuti, Siti Mardiana, Suswati, and Saipul Sihotang. 2023. “The Influence of Monoculture and Polyculture Planting Patterns on the Intensity of Pest Attacks by Helopeltis Sp. On Arabica Coffee of the Sigarar Utang Variety in North Tapanuli Regency”. Jurnal Penelitian Pendidikan IPA 9 (12):11296-301. https://doi.org/10.29303/jppipa.v9i12.5924.