They are also becoming pretty prominent on Twitter for those who indulge! Some great Yann Le Meur 'esque coaching infographics coming out recently.
Whilst on the subject of BelievePerform, I know they've taken a lot of inspiration from the PCA (Positive Coaching Alliance) over in America- building a large network of practitioners to add to their knowledge base. Though slightly different to PCA in that PCA often focus their attention on the character building of young people, & making their experience the positive one possible.
Both provide great, real life insight, pertinent for this next few months I'd suggest:
Skill mastery vs winning:
http://devzone.positivecoach.org/resource/video/focusing-mastery-vs-winning
Relative age affect / maturation
http://devzone.positivecoach.org/resource/article/keeping-your-kid-humble