jurnal-online.um.ac.id/article/do/detail-article/1/31/921

http://mediafunia.blogspot.com/2013/02/model-pembelajaran-kontekstual-react.html

http://abdussakir.wordpress.com/2011/02/09/pembelajaran-geometri-sesuai-teori-van-hiele-lengkap/

http://edmymatheducation.blogspot.com/2011/06/contextual-teaching-and-learning-with.html

http://wytr33.wordpress.com/2012/12/25/cooperative-learning-pembelajaran-kooperatif/