Córdoba, R., Escobar, L.P. and Guzmán, L.L. 2012. Factors associated with first trimester period absence from prenatal control in pregnant women from ESE San Sebastian in La Plata, Huila, 2009. RFS Revista Facultad de Salud. 4, 1 (Jan. 2012), 39–49. DOI:https://doi.org/10.25054/rfs.v4i1.118.