Quílez, J. 2007. Analysis of chemical equilibrium problems from exams to access university: Misconceptions and difficulties held by chemistry textbooks, students and teachers. Enseñanza de las Ciencias. Revista de investigación y experiencias didácticas. 24, 2 (Nov. 2007), 219–240. DOI:https://doi.org/10.5565/rev/ensciencias.3802.