Incoming Resources
- The study of twins, Peter Mittler
- Genetic and environmental influences on insomnia symptoms and associated cognition and arousal in young adults, Melanie Nicole Schneider
- Personality differences and biological variations, a study of twins, by Gordon Claridge, Sandra Canter and W.I. Hume
- The trouble with twin studies, a reassessment of twin research in the social and behavioral sciences, Jay Joseph
- Twins and the double, John Lash
- Schizophrenia and genetics, a twin study vantage point, by Irving I. Gottesman and James Shields ; with a contribution by Paul E. Meehl
- Twins, a practical guide to parenting multiples from conception to preschool, Katrina Bowman and Louise Ryan