Introduction to Probability, Dimitri P. Bertsekas and John N. Tsitsiklis, 2008 (Athena Scientific) - A widely used and rigorous textbook for introductory probability, providing a detailed academic explanation of the Poisson distribution and its mathematical foundations.
An Introduction to Statistical Learning with Applications in R, Gareth James, Daniela Witten, Trevor Hastie, Rob Tibshirani, 2013 (Springer) - This book provides a statistical learning perspective, offering context for how distributions like Poisson are used in modeling and discussing Poisson regression in a machine learning setting.
Generalized Linear Models, P. McCullagh, J. A. Nelder, 1989 Vol. 37 (Chapman and Hall)DOI: 10.1201/9780203753736 - The authoritative reference for generalized linear models (GLMs), which include Poisson regression, a key application mentioned for modeling count data in the course section.