Papagiannopoulos Δ, Digelidis Ν. The Teaching Approach TGFU and the Results of its Application in Primary and Secondary Education. ispe [Internet]. 2019 Jul. 31 [cited 2024 May 2];17(2):111-37. Available from: https://journals.lib.uth.gr/index.php/inquiries/article/view/1529