Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thanh vi » thanh va, thanh ve, nhanh vi
cac tuc » cac toc, cac tu, cac tac
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
tu sach » thu sach, su sach, te sach
so hoa » do hoa, so ha
tuc ta » tuc tap, tuc tao, tuc tat
ve cac » va cac, vien cac
o hoc » co hoc, mo hoc, so hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang ((o hoc) or (so hoa)). hieu ve cac tuc ta ((thanh vi) OR (hanh vi)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoc) OR (so hoa)). hieu ve cac tuc ta ((thanh vi) OR (hanh vi)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hoc) or (so hoa)). hieu ve cac tuc ta ((thanh vi) OR (hanh vi)) su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoc) or (so hoa)). hieu ve cac tuc ta ((thanh vi) OR (hanh vi)) su triet*.