Current teaching is that they were selected in 1919, not 1918. See the QFR in the 11/15/14 WT. One thing to point out in that QFR is that the "42 months" is taken as a literal length of time yet the 3.5 days is figurative. Both time-frames are part of the same prophecy. Makes no sense.
As others have mentioned, you can use JWFacts to find a lot of info. For the 1918/1919 debate, you can point to 607 not being the year that Jerusalem was destroyed. That messes up their entire timeline. See this article to prove it from WT literature.