SELECT C.CitationID As C_ID, S.Name AS Source, N.NameID AS N_ID, C.OwnerType AS C_Type
FROM CitationTable AS C
        LEFT JOIN
     SourceTable AS S ON S.SourceID = C.SourceID
        LEFT JOIN
     NameTable AS N ON N.NameID = C.OwnerID 
WHERE C.OwnerType = 7 -- AND N.NameID IS NULL         
ORDER BY S.Name;