Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
cua viet » ca viet, cua vat, cua dieu
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: so ((sac ky) or (sach y)) nang cau hoi. hieu va cam tuc va hanh vi ((cua viet) or (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sac ky) OR (sach y)) nang cau hoi. hieu va cam tuc va hanh vi ((cua viet) OR (hoa viet)).
• Adding a wildcard symbol may retrieve word variants: so ((sac ky) or (sach y)) nang cau hoi. hieu va cam tuc va hanh vi ((cua viet) or (hoa viet))*.