Perhaps you should try some spelling variations:
astronomy surveys » astronomy surveying, astronomy survives, autonomy survey
trials political » trials clinical
astronomy sergey » astronomy seven, astronomy large, astronomy society
astronomy survey » autonomy survey, astronomy surveying, astronomy survives

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: the patrick trials political ((astronomy sergey) OR (((astronomy surveys) OR (astronomy survey)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "the patrick trials political ((astronomy sergey) or (((astronomy surveys) OR (astronomy survey))))".
• Adding a wildcard symbol may retrieve word variants: the patrick trials political ((astronomy sergey) or (((astronomy surveys) OR (astronomy survey))))*.