For those with a strong math and stats background looking for structured resources on A/B testing, I recommend "Trustworthy Online Controlled Experiments" by Kohavi, Tang, and Xu, and "Statistical Methods in Online A/B Testing" by Georgi Georgiev. Additionally, Evan Miller's work and tools on A/B testing are highly insightful. For a broader understanding, delve into standard texts on experimental design and sampling, such as Donald Wheeler's "Understanding Variation" and Deming's "Some Theory of Sampling."