Ask HN: Facebook/abc.xyz referrals in Google Analytics, spam or real?

I have also got 2-3 referrals from http://abc.xyz :-D This is the parent company of Google! No way they are going to link to my Go language book. I also got spam links asking me to vote for Trump. How do I know which referrals are genuine? I know http://github.com referrals are real ones, but does facebook have any internal HN type tool maybe? where the book was posted?

my book's link is http://leanpub.com/antitextbookGo/; I also got "referral" from awesome-angularJS's github project, the funny thing is, why would angularJS have link to a Go language book which has exactly 0 lines of Angular in it. I am really confused since this is the first time I am using Google Analytics