Perhaps you should try some spelling variations:
extraction method » extraction methods (Expand search)
power functions » power function (Expand search), motor functions (Expand search), taper functions (Expand search)
and extraction » fluid extraction (Expand search)
functions and » function and (Expand search), functional and (Expand search)
python python » pythons python (Expand search), piton python (Expand search), pitons python (Expand search)
using codigo » using indigo (Expand search), using coding (Expand search), using codium (Expand search)

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: (( power functions AND extraction method ) OR ( using codigo python python programming ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( power functions and extraction method ) OR ( using codigo python python programming ))~".
• Adding a wildcard symbol may retrieve word variants: (( power functions and extraction method ) OR ( using codigo python python programming ))*.