Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
dinh dai » dinh dat, sinh dai, dinh dao
lanh ky » nganh ky, thanh ky, lanh lay
hanh ky » hanh kem
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va dinh » van dinh, va kinh, va tinh
cua tre » cua te, cuu tre, cua triet
xu va » xu van, tu va, su va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuat ((lanh ky) or (hanh ky)) nang xa hoi. ((hieu van) OR (hieu va)) chao xu va dinh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((lanh ky) OR (hanh ky)) nang xa hoi. ((hieu van) OR (hieu va)) chao xu va dinh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((lanh ky) or (hanh ky)) nang xa hoi. ((hieu van) OR (hieu va)) chao xu va dinh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thuat ((lanh ky) or (hanh ky)) nang xa hoi. ((hieu van) OR (hieu va)) chao xu va dinh dai cua tre*.