Perhaps you should try some spelling variations:
cua triet » su triet, va triet
hieu san » hieu van, hieu sau, chieu sang
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
duc van » duc va, duc tan, duc manh
hanh de » hanh ve, hanh kem
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
pham » phan

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

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