[Canadaoer] Chasing down this one open textbook...

Hi Everyone, I’m trying to recall an open textbook that a colleague at UofA is looking for. It was on display at the last BC open textbook summit, he thinks at the OpenStax display and it's about how to collaborate on the development of OER. At first I thought he meant the REBUS ebook on collaborating with students but that’s not the one. The plan is to have some printed open textbooks available at the Faculty of Sciences’ celebration of teaching as prizes and share that digital copies are freely available. Any suggestions of unique science OER or what this collaboration text is? Thanks so much! Krysta