Salazar-Estupiñán SA. Students’ Perceptions of Difficulties in Learning Mendel’s Laws in Biology in the Second Year of Unified General Baccalaureate. EKSIGMA [Internet]. 2026 Sep. 15 [cited 2026 Oct. 26];2(3):21-3. Available from: https://eksigma.com/index.php/principal/article/view/32