Sibling Rivalry And Toxic Parenting

1. Psychology Today: Toxic Parenting and Sibling Warfare. 
2. https://www.regain.us/advice/family/toxic-family-dynamics-the-signs-and-how-to-cope-with-them/
3. https://www.goodreads.com/work/quotes/3551-toxic-parents-overcoming-their-hurtful-legacy-and-reclaiming-your-life - "Enmeshment creates almost total dependence on approval and validation from outside yourself. Lovers, bosses, friends, even strangers become the stand-in for parents. Adults like Kim who were raised in families where there was no permission to be an individual frequently become approval junkies, constantly seeking their next fix."