Dionisio Martínez Soler

Dionisio Martínez Soler at

Obviously books related to topics of interest are good resources. You have also a good resource online at http://mathworld.wolfram.com/ You can also follow a free MOOC if you'd like a more guided and structured approach, try for example https://www.coursera.org, where you can find courses like this one: https://www.coursera.org/course/aofa

Christopher Allan Webber likes this.