Perhaps you should try some spelling variations:
cac vung » cac ung, cac chung, cach dung
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
hieu van » thien van, lieu va, hieu ve
sach thi » sach thu, sach tai, sach thieu
te sach » toc sach
vai cua » dai cua, hai cua, lai cua
cac vuc » cac nuoc, cac cuoc, cac quoc
hieu va » lieu va, hieu qua
cho hoc » co hoc, khoa hoc
cua cau » cua cac, cua chu, cua cay

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