Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
day thanh » dao thanh, dat thanh, da thanh
thuc day » thuc dan, thuc vat
dua tren » dung tren
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, cua thep
nang xa » nang x, lang xa, nang ma
cuu tre » cau tren, cau treo

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 ky nang xa hoi. hieu van nam thuc day thanh doi ((((cua tre) OR (dua tren))) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. hieu van nam thuc day thanh doi ((((cua tre) OR (dua tren))) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. hieu van nam thuc day thanh doi ((((cua tre) OR (dua tren))) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. hieu van nam thuc day thanh doi ((((cua tre) OR (dua tren))) or (cuu tre))*.