REMOVE

1. Topography
2. Atlas Map
3. Valais Region (Switzerland)

WHAT

1. Data Visualization (1)
2. Glaciers (1)
3. Historical (1)
4. National Atlas (1)

WHERE

1. Switzerland (1)
2. Valais Alps (Switzerland) (1)

WHO

1. Eidgenössische Landestopo … (1)
2. Imhof, Eduard, 1895-1986 (1)
3. Verlag der Eidgenössisch … (1)

WHEN

1. 1973 (1)
2. 1978 (1)