Halacha and Copywrite
Question
I am a teacher and have created some curriculum resources that I would like to sell. In order to encourage schools to buy my resources, I would like to give the principle a free sample to look at and discuss with her teachers. However, I do not want them to copy and distribute it. Is it a halachic violation to steal / reproduce/ share, intellectual property and creativity? What is the halachic violation ? What is the best way to word this on my product/resource?