Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
vat thanh » dat thanh, gat thanh, tat thanh
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
hieu van » thien van, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
doi cua » dai cua, hoi cua
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 nang xa hoi. ((hieu van) OR (hieu va)) 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 nang xa hoi. ((hieu van) OR (hieu va)) am thuc vat thanh doi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) am thuc vat thanh doi cua viet".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky nang xa hoi. ((hieu van) OR (hieu va)) am thuc vat thanh doi cua viet*.