FINDEISEN, D. Ene Käpp ali optimizem. Andragoška spoznanja, Ljubljana, SI, v. 4, n. 3-4, p. 69–70, 1998. DOI: 10.4312/as.4.3-4.69-70. Disponível em: https://journals.uni-lj.si/AndragoskaSpoznanja/article/view/6740. Acesso em: 6 dec. 2023.