Perhaps you should try some spelling variations:
components central » componente central (Expand search), components neutral (Expand search), componentes centrais (Expand search)
central program » dental program (Expand search), centro program (Expand search), cultural program (Expand search)
sampling method » sampling methods (Expand search)
and components » yield components (Expand search), blood components (Expand search)
using sampling » using subsampling (Expand search), using saline (Expand search), sinus sampling (Expand search)
method python » method method (Expand search), python python (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: (( code AND components central program ) OR ( using sampling method python programming ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( code and components central program ) OR ( using sampling method python programming ))~".
• Adding a wildcard symbol may retrieve word variants: (( code and components central program ) OR ( using sampling method python programming ))*.