Ramírez Amaya A, Sánchez Lara G. Descriptive Study of the Low Level of Performance in the Results of Plan 2015, (Mathematics, 6th Grade of Primary School) State of Veracruz. RUC [Internet]. 2016 Aug. 1 [cited 2026 Nov. 14];5:15-23. Available from: https://universita.ux.edu.mx/universita-ciencia/article/view/1148