Perhaps you should try some spelling variations:
da thanh » dao thanh, dat thanh, dam thanh
giau cua » gian cua, gia cua, dieu cua
hieu van » hieu va, thien van, lieu va
te sach » toc sach
va danh » va dinh, va dan, va hanh
dau tuc » dau tu, dao tuc, cau truc
van dau » van dao, phan dau
mang xa » lang xa, mang may, dang xay
cua tre » cua te, cuu tre, cua triet

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 y ((mang xa) or (nang x)) hoi. hieu van dau tuc ((da thanh) or (va danh)) giau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y ((mang xa) OR (nang x)) hoi. hieu van dau tuc ((da thanh) OR (va danh)) giau cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach y ((mang xa) or (nang x)) hoi. hieu van dau tuc ((da thanh) or (va danh)) giau cua tre*.