I am looking for a book/thesis I read about Ising models. I'm pretty sure it was done in the 1970 or maybe 1980s, since it was definitely pre-LaTeX (it looked type-written).
The book also included an introductory chapter on elementary probability. This chapter included the "airplane engine problem" (which $p$ of an engine failing makes a 2 engine plane preferable to a 4 engine plane).
I checked in Ross's Introduction to Probability Models, which includes the airplane problem, hoping for a reference, but I didn't find one.