Remove Duplicate Results

Query issue

[librarychick]

Hello and thanks in advance for any help you can give me!

This is my query:

$sdbh = sycom("select distinct a15.title title, a11.author author, a14.processed processed, a12.creation_date creation_day, a13.collection collection, a16.descr descr
from rv_bib_author a11, rv_bib_control a12, rv_item a13, rv_isbn a14, rv_title_inverted a15, collection a16 where a11.bib_id = a12.bib_id and a11.bib_id = a13.bib_id and a11.bib_id = a14.bib_id and a11.bib_id = a15.bib_id and a13.collection = a16.collection and (a13.collection in ('f', 'nf', 'b', 'gn', 'le', 'leb', 'lef', 'lelp', 'lh', 'lhb', 'lhf', 'lp', 'lpb', 'lpf', 'lpm', 'lpsf', 'lpw', 'm', 'os', 'pb', 'sf', 'w')and (a14.processed IS NOT NULL) and a12.creation_date between '03/01/2009' and '05/30/2019') order by a12.creation_date desc");

My problem is that I want distinct titles, but not distinct ISBN numbers... because each title may have 2-5 different ISBNs, they return a duplicate record for each unique ISBN.

How can I get a distinct title but not use the distinct criteria for ISBN?

Thanks again!