Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
hanh te » hanh tu, hanh ve, hanh de
cuu tac » cuu dac, cuu cac, cuu xac
nang xa » nang x, lang xa, nang ma
te sach » toc sach
te cua » tue cua, le cua, de cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (te sach)) ky nang xa hoi. hieu van ((cuu thuc) OR (cuu tac)) vat hanh te cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang xa hoi. hieu van ((cuu thuc) OR (cuu tac)) vat hanh te cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang xa hoi. hieu van ((cuu thuc) OR (cuu tac)) vat hanh te cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang xa hoi. hieu van ((cuu thuc) OR (cuu tac)) vat hanh te cua te*.