Stuff

with lentele2 as (select lentele1.isbn, knyga.pavadinimas, lentele1.skaicius from (select isbn, count(isbn) as skaicius from egzempliorius group by isbn) as lentele1, knyga where lentele1.isbn=knyga.isbn) select l2.pavadinimas, l2.isbn from lentele2 l2, (select max(skaicius) as maxsk from lentele2) maxl where l2.skaicius=maxl.maxsk