00221nam a2200085Ia 4500 201217s9999 xx 000 0 und d Burger, W. Radar Observer's Handbook For Merchant Navy Officers BK 7383 7383 0 0 0 0 CL 2020-12-17 623.8933 B9544 PM02524 2020-12-17 2020-12-17 BK