271. Sheet 84-D-6, Bangladesh 1:50,000 topographic maps, 1988 Maps University Of California Berkeley Restricted content 1988. Land Info (Firm), Sārve aba Bāṃlādeśa, and Survey of Bangladesh. This map is Sheet 84-D-6 (2nd Edition) of the topographic map series Bangladesh 1:50,000 topographic maps, issued by Sārve aba Bāṃlādeśa, the ... Land Info (Firm).