Here are two good resources about Flaky tests: How to Deal With and Eliminate Flaky Tests [1] An Empirical Analysis of Flaky Tests [2]
[1] https://semaphoreci.com/community/tutorials/how-to-deal-with-and-eliminate-flaky-tests [2] http://mir.cs.illinois.edu/~qluo2/fse14LuoHEM.pdf