Talis 2018 Results : Teachers and School Leaders as Lifelong Learners. Volume I. Paris : OECD, 2019. 216 s. TALIS. Available on Internet: <https://www.oecd-ilibrary.org/education/talis-2018-results-volume-i_1d0bc92a-en> ISBN 978-92-64-75256-6.