--- /dev/null
+create temporary table callnumbers ( callnumber varchar(255) primary key, count int not null ) ;
+insert into callnumbers select itemcallnumber,count(itemcallnumber) from items where itemcallnumber like 'BB%' group by itemcallnumber ;
+
+-- Duple signature
+SELECT count(biblio.biblionumber) as primjeraka,
+ callnumbers.count as signatura,
+ items.itemcallnumber,
+ biblio.author,biblio.title,biblioitems.publicationyear,biblioitems.number as svezak,biblio.biblionumber,
+ items.copynumber
+FROM items
+LEFT JOIN biblioitems on (items.biblioitemnumber=biblioitems.biblioitemnumber)
+LEFT JOIN biblio on (biblioitems.biblionumber=biblio.biblionumber)
+LEFT JOIN callnumbers on itemcallnumber = callnumbers.callnumber
+WHERE items.itemcallnumber IS NOT NULL and items.itemcallnumber like 'BB%'
+GROUP BY biblio.biblionumber
+having primjeraka < signatura
+order by items.itemcallnumber ;