Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tru nang » tra nang, tri nang, truc nano
nang cho » nang chon, ngang cho, nang cao
van hanh » van thanh, ban hanh, van anh
sach tru » sach truc, sach thu, sach tu
cac vuc » cac nuoc, cac vung, cac cuoc
vai cua » dai cua, hai cua, lai cua
vuc van » duc van, luc van, thuc van
hieu va » lieu va, hieu qua
hieu ve » hieu van
cho hoc » co hoc, khoa hoc
vi cua » di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach tru nang cho hoc. ((hieu ve) or (hieu va)) cac vuc van hanh ((vi cua) OR (vai cua)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tru nang cho hoc. ((hieu ve) OR (hieu va)) cac vuc van hanh ((vi cua) OR (vai cua)) cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tru nang cho hoc. ((hieu ve) or (hieu va)) cac vuc van hanh ((vi cua) OR (vai cua)) cau*".