R. Antunes, N. Couto, A. Vitorino, D. Monteiro, D. A. Marinho, and L. Cid, “Physical activity and affect of the elderly: Contribution to the validation of the Positive and Negative Affect Shedule (PANAS) in the Portuguese population”, J. Hum. Sport Exerc., vol. 15, no. 2, pp. 330–343, Jun. 2020.