TY  - BOOK
AU  - "Norway, Central Bureu of Statistics"
ED  - "Norway, Central Bureu of Statistics"
TI  - "Statistical year book 1956, 75th issue"
U1  - "E.573s.N56, J6" 
PY  - 1956///
CY  - OSLo
PB  - Statistik sentralbyra      
ER  -