REMOVE

1. Cramer
2. Brown
3. DeFerrer
4. Bourne, A.

WHAT

1. Atlas Map (1)
2. Physical (1)
3. World Atlas (1)

WHERE

1. Chad (1)
2. Egypt (1)
3. Niger (1)
4. Northeast Africa (1)
5. Sudan (1)

WHO

1. USSR (1)
2. USSR (Union of Soviet Soc … (1)

WHEN

1. 1967 (1)