A Billion Voices: China's Search for a Common Language tells the story of the creation of Putonghua, or Mandarin, which is an interesting read for both Chinese and foreigner students of the language.

The book is written by American linguist David Moser, who has spent more than 30 years studying Chinese. It is now only selling as an e-book but will be available in paperback in October.

Currently, Moser is teaching at Capital Normal University in Beijing, where he coordinates a program for foreign students coming to China for summer courses.