Using Parental Ratings to Study the Etiology of 3-year-old Twins’ Problem Behaviors: Different Views or Rater Bias? - Van Der Valk, J. C.; Van Den Oord, E. J. C. G.; Verhulst, F. C.; Boomsma, D. I. (Blackwell Publishers Ltd., 2001)
http://dx.doi.org/10.1111/1469-7610.00788
Keywords: WW-YZ; CL-CZ