P. L.R. Sousa, F. M. Oliveira, C. L. Horta, F. R. Sousa, A. S. Torres, and E. C. Pinheiro, “The genesis of religious thought in childhood - I. A Piagetian perspective”, Rev. Razão e Fé, vol. 4, no. 1, pp. 73-80, May 2019.