As the wife of a scientist (in training, about to graduate with his Masters in Wildlife and Fisheries Management) I am learning that if I can't cite a source from a peer-reviewed journal than my argument doesn't count. If I just say something like "Oh, I read online somewhere the other day that (fill in the blank with some interesting tidbit of info)" his response is often "Oh yeah? Says who? Did that come from a peer reviewed journal?" So, I was really excited to discover recently that there is a real, peer reviewed journal dedicated to PLAY! It is called The American Journal of Play and it is "a forum for discussing the history, science, and culture of play. The Journal aims to increase awareness and understanding of the role of play in learning and human development and the ways in which play illuminates cultural history." Source
All of the issues of this journal are available for free on their website, which is in linked in the first paragraph of this post. If you want to see what kinds of things the journal has, here is a list of some interesting looking articles.
One thing that makes this journal especially interesting is the wide range of topics they cover. It seems to me that just about anyone could find an article that interests them. Just in the most recent issue, there are articles on the influence of play in the professional work place, the influence of play on cartoon drawing, introducing autistic children to playing in group settings, and a study of play in monkeys, just to name a few.
Now, when you tell someone something interesting you learned about the importance of play, you can have the knowledge that your info came from a peer reviewed source.