https://insertlearning.com/v1/lesson/5f42c0106dde50d67c424a03
https://psychology.iresearchnet.com/developmental-psychology/developmental-psychology-research-methods/experimental-method/
https://www.qualitative-research.net/index.php/fqs/article/view/466/996
https://www.iedunote.com/group
https://www.iedunote.com/group
https://www.tutorialspoint.com/organizational_behavior/organizational_behavior_groups.htm
https://www.slideshare.net/mobile/DisneyPrincesses/group-structure-69755073
https://www.studyandexam.com/attitude-meaning.html
http://psychology.iresearchnet.com/social-psychology/attitudes/attitude-change/
https://www.yourarticlelibrary.com/organization/attitude/top-3-theories-of-attitude-with-diagram/63835