Remove the books that are mostly too general introductions for novice programmers (the syntax etc). Remove the poorly edited, self published free ebooks. Remove the german language books.
Now divide by the number of C++ books published in the last decade.
No books?
Go in Action; Evan Shaw; Manning; http://www.manning.com/shaw/
An Introduction to Programming in Go; Caleb Doxsey; http://www.golang-book.com
Network Programming with Go; Jan Newmarch; Free e-book; http://jan.newmarch.name/golang/
Programming in Go: Creating Applications for the 21st Century; Mark Summerfield; Addison-Wesley Professional; http://qtrac.eu/gobook.html
The Way To Go: A Thorough Introduction To The Go Programming Language; Ivo Balbaert; iUniverse
The Go Programming Language Phrasebook; David Chisnall; Addison-Wesley Professional
The Go Programming Language (upcoming); Brian Ketelsen; The Pragmatic Bookshelf; http://pragprog.com/book/bkgo/the-go-programming-language
Learning Go; Miek Gieben; Free e-book; http://www.miek.nl/projects/learninggo/index.html
Systemprogrammierung in Google Go: Grundlagen, Skalierbarkeit, Performanz, Sicherheit; Frank Müller; Dpunkt Verlag; http://dpunkt.de/buecher/3449.html
Programmierung in Google Go: Einstieg, Beispiele und professionelle Anwendung; Rainer Feike, Steffen Blass; Addison-Wesley