Nasution, A. M. A.; Ngatirah; Oktavianty, H.; Nasution, N. E. A. The Effect of Variations in the Water-to-Coffee-Powder Ratio on the Water Content and Caffeine Content of Sigarar Utang Instant Arabica Coffee. J. Sci. Technol. Educ. 2023, 2, 75-80.