select distinct substring(name,1,1) from stamps ,paper_master where year(stamps.issue_date)=1977 and month(issue_date)=4 and paper_master.paper_code=stamps.paper_code and paper_master.paper='Unwatermarked adhesive stamp paper' and stamps.serial_no='0845' order by substring(name,1,1)
IndianPost
Issue Date >> year >> 1977 >> month >> April >> Paper >> Unwatermarked adhesive stamp paper >> Serial Number >> 0845 >> Alpha >> M >>