Genetic and environmental influences on temperament in the first year of life: the Puerto Rico Infant Twin Study (PRINTS).
Silberg JL, Miguel VF, Murrelle EL, Prom E, Bates JE, Canino G, Egger H, Eaves LJ. Genetic and environmental influences on temperament in the first year of life: the Puerto Rico Infant Twin Study (PRINTS). Twin Res Hum Genet. 2005 Aug; 8(4):328-36.