Wolański, N. ., A. . Rojas, G. . Valentin, and A. Siniarska. “Each Child and Each of Its Features Has a Specific Pace of Development, Modified by the Living Conditions in a Given Period. (Report 2 of a Biennial Monthly Survey in Yucatan, Mexico)”. Studia Ecologiae Et Bioethicae, vol. 2, no. 1, Dec. 2004, pp. 47-74, doi:10.21697/seb.2004.2.1.02.