select distinct substring(name,1,1) from stamps ,paper_master where year(stamps.issue_date)=1981 and month(issue_date)=5 and paper_master.paper_code=stamps.paper_code and paper_master.paper='Unwatermarked adhesive stamp paper' order by substring(name,1,1)
IndianPost
Issue Date >> year >> 1981 >> month >> May >> Paper >> Unwatermarked adhesive stamp paper >> Alpha >> B >>