Treasure of the rocks /
Guggenheimer, Michael.
Oberli, Urs.
Zittel, Karl Alfred von,1839-1904.
St. Gallen : Typotron, represented by VGS Verlagsgemeinschaft,
c1984.
"English translation by Andew Bluhm ... Photos on pp. 17 to 23 by Urs Oberli; illustration on p. 24 ... by Karl A. von Zittel." - Colophon.
Oberli, Urs.