I bought a German book about selective mutism, Mutismus im Kindes-, Jugend- und Erwachsenenalter. It's a thin book. Only 64 pages.
I have an interest in German literature on selective mutism. As far as I know, German has the longest history of research on selective mutism. In addition, there is a self-help group in German. I guess German specialists have unique know-how on selective mutism.
I bought this book because
a) It's affordable.
b) It's only 64 pages. So, it seems to be easy to read.
c) It deals with adults with selective mutism.
But I can't read German. This book is the first German book I bought. So, when I read the German book, I use Babel Fish to translate German into English. Babel Fish is very useful. But it's a rough translation by a machine translator. It's difficult to read. :(
The book seems to contain fundamental knowledge about selective mutism. It includes many photographs and illustrations, so it's easy to read.