Lupşa, Liana. “Linear Integer and Linear Rational Inequalities”. Anal. Numér. Théor. Approx. 19, no. 1 (February 1, 1990): 49–52. Accessed April 28, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1990-vol19-no1-art8.