Hansen M., Lund M.S., Pedersen J., Christensen L.G. (2004): Gestation length in Danish Holsteins has weak genetic associations with stillbirth, calving difficulty, and calf size. Livestock Production Science 91: 23-33.10.1016/j.livprodsci.2004.06.007
Lopez de Maturana E., Wu X.-L., Gianola D., Weigel K.A., Rosa G.J.M. (2009): Exploring Biological Relationships Between Calving Traits in Primiparous Cattle with a Bayesian Recursive Model. Genetics 181: 277-287.10.1534/genetics.108.094888262117518984571
Xing Ch., Li Y., Zhang K., Wang L. (2011): Shadow detecting using particle swarm optimization and the Kolmogorov test. Computers and Mathematics with Applications 62: 2704-2711.10.1016/j.camwa.2011.06.052