Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
xang cho » sang cho, hang cho, tang cho
hieu va » lieu va, hieu qua
hanh di » hanh vi, hanh de, hang di
vuc van » duc van, luc van, thuc van
cac vuc » cac nuoc, cac vung, cac cuoc
cua cau » cua cac, cua chu, cua cay
sach ty » sach tu, sach thu, xach tay
hieu ve » hieu van
cho hoc » co hoc, khoa hoc
di cua » dai cua, doi cua, de 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 ty) or (sach y)) xang cho hoc. ((hieu ve) OR (hieu va)) cac vuc van hanh di cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ty) OR (sach y)) xang cho hoc. ((hieu ve) OR (hieu va)) cac vuc van hanh di cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ty) or (sach y)) xang cho hoc. ((hieu ve) OR (hieu va)) cac vuc van hanh di cua cau*".