Dlouhá, Jana, Eduard Petiška, Jiří Dlouhý, and Dana Kapitulčinová. “Opportunities and Risks of the Use of Open Education Resources in Environmental Disciplines at University Level in the Czech Republic: A Criteria for Assessing Quality”. Envigogika 10, no. 4 (December 5, 2015). Accessed May 23, 2019. https://envigogika.cuni.cz/index.php/Envigogika/article/view/503.