Studies on the humic, acid Lake Gribso /
by Kaj Berg and Ib Clemens Petersen. With contributions by Kaj Hansen, Per Wolthers, and Gunnar Nygaard. Translation by Annie I. Fausboll.
- Copenhagen : Munksgaard, 1956.
- 273 p. : ill. , 21 plates, maps. ; 26 cm.