Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vat hanh » vat thanh, van hanh, va hanh
hanh tue » hanh tu, hanh tuyen, hanh theo
te sach » toc sach
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
cuu tac » cuu dac, cuu cac, cuu xac
cua tu » cua tuc, cua su, cua cu

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

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