Perhaps you should try some spelling variations:
practical astronomy » nautical astronomy, positional astronomy
astronomy studies » astronomy study, economy studies, astronomy status
optical astronomy » nautical astronomy, spherical astronomy, positional astronomy
debois practical » ferris practical, boss practical, debt practical
astronomy during » astronomy dialling, astronomy meeting, economy during
patrick debois » patrick dublin
patrick mons » patrick moyes, patrick bond, patrick mpondo
mons optical » ions optical, mono optical, cmos optical

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 debois practical astronomy studies ) OR ( the patrick mons optical astronomy during )).
• Adding a wildcard symbol may retrieve word variants: (( the patrick debois practical astronomy studies ) or ( the patrick mons optical astronomy during ))*.