Perhaps you should try some spelling variations:
practical astronomy » optical astronomy, positional astronomy
astronomy sergey » astronomy survey, astronomy surveys, astronomy seven
lens practical » less practical, owens practical, plans practical
lord nautical » board nautical, logs nautical, hoc nautical
patrick lens » patrick glenn, patrick arens, patrick lentz
patrick lord » patrick bond, patrick ll.d, patrick gordon

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 lens practical astronomy sergey ) OR ( the patrick lord nautical astronomy sergey )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick lens practical astronomy sergey ) or ( the patrick lord nautical astronomy sergey ))*.