Reference error in 3.2.2

[F-Gaertner]

In chapter 3.2.2, the

flights |> 
  filter(month == 1 | 2) 

error is mentioned and then a reference where it is explained follows. However, the reference incorrectly leads to section 15.6.2, while it should lead to section 12.3.2.

[mine-cetinkaya-rundel]

This is now fixed, thanks!