SpringerLink (Online service), Krafft, A. M., Perrig-Chiello, P., & Walker, A. M. (2018). Hope for a Good Life: Results of the Hope-Barometer International Research Program (1st ed. 2018.). Springer International Publishing : Imprint: Springer. https://doi.org/10.1007/978-3-319-78470-0
Παραπομπή σε μορφή Chicago (17η εκδ.)SpringerLink (Online service), Andreas M. Krafft, Pasqualina Perrig-Chiello, και Andreas M. Walker. Hope for a Good Life: Results of the Hope-Barometer International Research Program. 1st ed. 2018. Cham: Springer International Publishing : Imprint: Springer, 2018. https://doi.org/10.1007/978-3-319-78470-0.
Παραπομπή σε μορφή MLA (8th εκδ.)SpringerLink (Online service), et al. Hope for a Good Life: Results of the Hope-Barometer International Research Program. 1st ed. 2018. Springer International Publishing : Imprint: Springer, 2018. https://doi.org/10.1007/978-3-319-78470-0.
