Add, if in amazon.com, some books. Hermann Buhl talks a lot about this mountain and his N face ascents in the book "Achttausender drüber und drunter", Nymphenburger Verlagshandlung, Munich, 1954. Recently translated into Spanish as "Del Tirol al Nanga Parbat", Ediciones Desnivel, Madrid, 2001.
Good luck with your adoption
I am waiting for the new book addition interface which will make it possible to add non-amazon.com books (see message bords). I will look if there is something on amazon.com but I doubt it.
I adopted recently this page and I tried to improve it. Thank you, Diego, for your interest !