This article explains multiple ways to calculate AUC mathematically along with step by step implementation guide in Python, SAS and R.
How to Interpret a ROC Curve (With Examples) - Statology
ROC Curve explained using a COVID-19 hypothetical example: Binary & Multi-Class Classification tutorial, by Serafeim Loukas, PhD
Methods to determine area under curve
GraphPad Prism 10 Statistics Guide - Area under the curve
Area under the Curve - an overview
How to Use ROC Curves and Precision-Recall Curves for Classification in Python
Guide to AUC ROC Curve in Machine Learning
ROC curves and Area Under the Curve explained (video)
Understanding AUC - ROC Curve, by Sarang Narkhede
The Beginners' Guide to the ROC Curve and AUC, by Chetan Ambi