Talvez deva tentar algumas variações de ortografia:
vpython collisions » vpython colisoes (Expandir a busca), proton collisions (Expandir a busca), photon collisions (Expandir a busca)
decrease tutorial » decrease arterial (Expandir a busca), decrease bacterial (Expandir a busca), decrease total (Expandir a busca)
collisions python » collisions within (Expandir a busca), collisions with (Expandir a busca), collisions on (Expandir a busca)
tutorial program » tutoring program (Expandir a busca), material program (Expandir a busca), social program (Expandir a busca)
python python » pythons python (Expandir a busca), piton python (Expandir a busca), pitons python (Expandir a busca)
decrease akt » decrease at (Expandir a busca), decrease and (Expandir a busca), decrease after (Expandir a busca)
akt decrease » and decrease (Expandir a busca), not decrease (Expandir a busca), any decrease (Expandir a busca)

Você pode obter mais resultados ajustando o argumento de busca.

• Remover as aspas pode possibilitar buscas mais amplas: (( decrease akt decrease tutorial program ) OR ( vpython collisions python python programming ))~.