Perhaps you should try some spelling variations:
"union assembly" » "unit assembly", "units assembly", "junction assembly"
"down assembly" » "darwin assembly", "town assembled", "toxin assembly"
"non assembly" » "exon assembly", "fin assembly", "gen assembly"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("non assembly") OR ("down assembly"))) OR ("union assembly")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"non assembly\") OR (\"down assembly\"))) or (\"union assembly\"))".
• Removing quotes may allow a broader search: (((( non assembly ) OR ( down assembly ))) or ( union assembly )).
• Adding a wildcard symbol may retrieve word variants: (((("non assembly") OR ("down assembly"))) or ("union assembly"))*.