Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
danh va » doanh va, hanh va, dan va
ma hoi » mai hoi, xa hoi, ma hoa
ve dam » ven dam, ke dam, va dam
dam tu » nam tu, cam tu, tam tu
anh va » hanh va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) OR (toc sach)) ky nang ma hoi. hieu ve dam tu va ((danh va) or (anh va)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang ma hoi. hieu ve dam tu va ((danh va) OR (anh va)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang ma hoi. hieu ve dam tu va ((danh va) or (anh va)) su triet".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang ma hoi. hieu ve dam tu va ((danh va) or (anh va)) su triet*.