Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
toc sach » hoc sach, doc sach, thuoc sach
thi hang » thi hanh, thi nang, thi hong
hang cho » sang cho, hang khoa, phong cho
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
vai cua » dai cua, hai cua, lai cua
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
cua cau » cua cac, cua chu, cua cay
hieu va » lieu va, hieu qua
cho hoc » co hoc, khoa hoc

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)) thi hang cho hoc. ((hieu va) or (hieu van)) cac vuc van hanh vai cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) thi hang cho hoc. ((hieu va) OR (hieu van)) cac vuc van hanh vai cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) thi hang cho hoc. ((hieu va) or (hieu van)) cac vuc van hanh vai cua cau*".