Utjecaj programa pozitivne psihologije na dobrobit (optimizam, nada, životno zadovoljstvo) i uspjeh učenika trećeg razreda osnovne škole : doktorski rad = The impact of the positive psychology program to the well-being (optimism, hope, life satisfaction) and the achievement of third grade students in the primary school : doctoral thesis - Šarančić, Snježana (2015)