Useful resources
Learning - Wikipedia
https://en.wikipedia.org/wiki/Relationships_among_probability_distributions
https://en.wikipedia.org/wiki/Gamma_function
https://en.wikipedia.org/wiki/Unbiased_estimation_of_standard_deviation
https://en.wikipedia.org/wiki/Bessel%27s_correction
https://en.wikipedia.org/wiki/Consistent_estimator
https://en.wikipedia.org/wiki/Moment-generating_function#Calculations_of_moments
https://www.statlect.com/probability-distributions/chi-square-distribution
Learn more facts/properties from Wikipedia and Statlect, the free digital textbook of statistics with proofs.
Remember you can print out all the stuff and take it to the exam.
Proofs and problem-solving - Stackexchange
http://math.stackexchange.com/
If you have a question and are too shy to ask Harald and me, ask the internet. But chances are someone already asked that question, and there are many solutions provided on stackexchange. The best solution is the shortest one.