ROCA-FERNÁNDEZ, A. I.; FERRIS, C. P.; GONZÁLEZ-RODRÍGUEZ, A. Short communication. Behavioural activities of two dairy cow genotypes (Holstein-Friesian vs. Jersey x Holstein-Friesian) in two milk production systems (grazing vs. confinement). Spanish Journal of Agricultural Research, v. 11, n. 1, p. 120-126, 5 Feb. 2013.