Intermediate Microeconomics With Calculus (PDF) by Hal Varian is very rigorous and modern―now with calculus integrated into the main textbook.
The #1 textbook is still the most modern presentation of the subject and gives college students tools to develop the problem-solving skills they need for the course, and beyond.
NOTE: This sale only includes the ebook Varian’s Intermediate Microeconomics With Calculus in PDF. No access codes included.