Mathematical background (limits, series, order relations and rates of convergence, continuity, sets)
Measure theoretic foundations of probability (probability triplets, random variables, independence, expected values, change of variable)
Stochastic convergence (almost sure convergence, convergence in probability, convergence in distribution, laws of large numbers, central limit theorems, non-iid stochastic variables)
Rosenthal, J.S., (2006), A First Look at Rigorous Probability Theory, 2nd ed., World Scientific. Lehmann, E.L., (1999), Elements of Large Sample Theory, Springer.