Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van phat » va phat, van chat, van phan
phat duc » pham duc, phan duc, phan duoc
va triet » va thiet, va trien, ve triet
cua viet » ca viet, hoa viet, cua vat
nang xa » lang xa, nang ma, mang xa
va hanh » van hanh, va thanh, va danh
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky

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

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