Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
doc sach » hoc sach, toc sach, nuoc sach
nang cho » nang chon, ngang cho, sang cho
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
van anh » tuan anh, van minh
cua cau » cua cac, cua chu, cua cay
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: doc sach ty ((nang cho) or (nang cao)) hoc. hieu va cac duc ((van anh) OR (van thanh)) di cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty ((nang cho) OR (nang cao)) hoc. hieu va cac duc ((van anh) OR (van thanh)) di cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty ((nang cho) or (nang cao)) hoc. hieu va cac duc ((van anh) OR (van thanh)) di cua cau*".