Under the supervision of Katie Hall, we adopted and edited in PreTeXt an open educational resource textbook for the University of Connecticut's Business Calculus course. I contributed to the writing of the special sections 1.6 Mathematical Modeling and 4.1 Elasticity of Demand to meet the course requirements. The textbook can be found below.
Here is a collection of open educational resources that I consider valuable.
WeBWorK - The Mathematical Association of America (MAA) offers a free online homework platform with pre-built problem sets for many standard courses.