amazon link: https://www.amazon.com/Learning-OpenCV-Computer-Vision-Library/dp/1491937998/ref=sr_1_1?crid=L2B7E0JWFJYD&keywords=learning+opencv+3+computer+vision+in+c%2B%2B+with+the+opencv+library&qid=1569131379&s=gateway&sprefix=learning+open%2Caps%2C211&sr=8-1

bought on amazon 2 years ago, now for sale at $25, free delivery on campus