González Gutiérrez, José Luis, Cecilia Peñacoba Puente, Ricardo Moreno Rodríguez, Almudena López López, and Lilian Velasco Furlong. “Nursing Motives for Helping Scale (N-MHS): Reliability and Validity”. The Spanish Journal of Psychology, vol. 9, vol. 9, no. 1, 2006, pp. 103-12, https://revistas.ucm.es/index.php/SJOP/article/view/SJOP0606120103A.