PISA 2015 results : excellence and equity in education. Volume I. Paris : OECD, 2016. 489 s. PISA. Available on Internet: <http://www.oecd-ilibrary.org/education/pisa-2015-results-volume-i_9789264266490-en> ISBN 978-92-64-26732-9. [Copy count : 1, currently available 1, at library only 0]