(en) Kristin Davies, Linda R. Tropp, Arthur Aron et Thomas F. Pettigrew, « Cross-Group Friendships and Intergroup Attitudes: A Meta-Analytic Review », Personality and Social Psychology Review, vol. 15, no 4, , p. 332–351 (ISSN1088-8683 et 1532-7957, DOI10.1177/1088868311411103, lire en ligne, consulté le ).
(en) Maurice H. Yearwood, Amy Cuddy, Nishtha Lamba et Wu Youyou, « On wealth and the diversity of friendships: High social class people around the world have fewer international friends », Personality and Individual Differences, vol. 87, , p. 224–229 (DOI10.1016/j.paid.2015.07.040, lire en ligne, consulté le ).
elsevier.com
linkinghub.elsevier.com
(en) Maurice H. Yearwood, Amy Cuddy, Nishtha Lamba et Wu Youyou, « On wealth and the diversity of friendships: High social class people around the world have fewer international friends », Personality and Individual Differences, vol. 87, , p. 224–229 (DOI10.1016/j.paid.2015.07.040, lire en ligne, consulté le ).
illinois.edu
worldhistoryconnected.press.illinois.edu
Toye, David L., « The Emergence of Complex Societies: A Comparative Approach », World History Connected, vol. 11, no 2, (lire en ligne [archive du ], consulté le )
(en) Kristin Davies, Linda R. Tropp, Arthur Aron et Thomas F. Pettigrew, « Cross-Group Friendships and Intergroup Attitudes: A Meta-Analytic Review », Personality and Social Psychology Review, vol. 15, no 4, , p. 332–351 (ISSN1088-8683 et 1532-7957, DOI10.1177/1088868311411103, lire en ligne, consulté le ).
(en) Kristin Davies, Linda R. Tropp, Arthur Aron et Thomas F. Pettigrew, « Cross-Group Friendships and Intergroup Attitudes: A Meta-Analytic Review », Personality and Social Psychology Review, vol. 15, no 4, , p. 332–351 (ISSN1088-8683 et 1532-7957, DOI10.1177/1088868311411103, lire en ligne, consulté le ).
Toye, David L., « The Emergence of Complex Societies: A Comparative Approach », World History Connected, vol. 11, no 2, (lire en ligne [archive du ], consulté le )