Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh va » thanh van, hanh va, thanh ha
cham hoc » chat hoc, cham hoi, cho hoc
sach ty » sach y, sach tu, sach thu
te sach » toc sach
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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 ty ((nang ma) or (sang ma)) hoa. hieu qua ((cham hoc) OR (cham soc)) van thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((nang ma) OR (sang ma)) hoa. hieu qua ((cham hoc) OR (cham soc)) van thanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((nang ma) or (sang ma)) hoa. hieu qua ((cham hoc) OR (cham soc)) van thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((nang ma) or (sang ma)) hoa. hieu qua ((cham hoc) OR (cham soc)) van thanh va cua tre*.