Páez, Christian, Marvin Abarca, Leonel Chaves, Alexander Hernández, Gabriela Calderón, Federico Mora, Jeremías Ramírez, et al. 2020. “Test Problems and Solutions XXX Costa Rican Math Olympiad, 2018: Problemas De exámenes Y Soluciones XXX Olimpiada Costarricense De Matemática, 2018”. Mathematics, Education and Internet Journal 20 (2). https://doi.org/10.18845/rdmei.v20i2.5047.