Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
thanh doi » thanh loi, thanh moi, thanh do
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
hieu van » hieu va, thien van, lieu va
cua viet » ca viet, hoa viet, cua vat
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
doi cua » dai cua, hoi cua
van am » van nam, van lam, van dam
thuc » thu

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) or (doc sach)) ky lang xa hoi. hieu van am thuc vat thanh doi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky lang xa hoi. hieu van am thuc vat thanh doi cua viet.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky lang xa hoi. hieu van am thuc vat thanh doi cua viet*.