Can you give me the names of those documents?
SELECT document_name FROM documents EXCEPT SELECT t1.document_name FROM documents AS t1 JOIN document_sections AS t2 ON t1.document_code   =   t2.document_code JOIN document_sections_images AS t3 ON t2.section_id   =   t3.section_id
names of those documents refers to document_name; EXCEPT is used to return rows from the first SELECT statement that aren't returned by the second SELECT statement; documents without images in any of their sections can be identified using the JOINs and EXCEPT.