Ek-Mex, J. E., J. C. Segura-Correa, and A. Alzina-López. “Effect of Reduced or Increased Number of Pigs Born Alive at Second Farrowing on Lifetime Productivity of Sows in Southeastern Mexico”. Archivos De Medicina Veterinaria, vol. 48, no. 2, Aug. 2016, pp. 243-6, doi:10.4067/S0301-732X2016000200016.