Learning Materials For All Devices! Textbooks The Language Conservancy and the MHA Language Project print numerous textbooks and materials for classroom use or for learning from home. Audio CDs We are working on recording audio CDs to accompany textbooks and provide proper pronunciation for students. Apps Language apps are our way of providing you with Hidatsa language tools when and where you need them. Posters & more Show your support of the Hidatsa language with a language warrior T-shirt, a poster for the classroom, and more!