A friend of mine needs to know what this kind of binding is termed (technically) -- The book are from Europe...
In case people here aren't fast and/or accurate enough:http://bookbindingforum.com/forum/http://cornerbindery.blogspot.com/2007/07/bookbinding-forums.html
In Europe we call it Schweizer Brochure (Holland) or Schweizer Broschur (Germany) with sewn binding and open back. You can choose the color of the yarn and some binders also can color the glue that is used. I have seen a translation in English where it is called Swiss Brochure.