Rerum Naturalium Fragmenta
No.1 (1896) - No.20 (1899)
No.21 (1900) - No.40 (1923)
No.41 (1924) - No.60 (1928)
No.61 (1928) - No.80 (1933)
No.81 (1934) - No.100 (1937)
No.101 (1937) - No.120 (1937)
No.121 (1938) - No.200 (1957)
No.201 (1957) - No.300 (1974)
No.301 (1975) - No.400 (1990)
No.401 (1991) -
PICTURES - Fényképek
Iz2 Vatnajökul
Vatnajökull Area, Iceland
P8 Sorris Sorris
Semidesert Region of Sorris Sorris, Namibia
U1 Arctic
Snow & Ice in Greenland, Canada & US
U8 Seal Rocks, Calif
