Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
va hanh » van hanh, va thanh, va danh
sai ky » sac ky
va cau » van cau, va cac, va dau
vi cua » vai cua, di cua

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 y) or (sai ky)) ((nang xa) or (nang x)) hoi. hieu va cau truc va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach y) OR (sai ky)) ((nang xa) OR (nang x)) hoi. hieu va cau truc va hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: tu ((sach y) or (sai ky)) ((nang xa) or (nang x)) hoi. hieu va cau truc va hanh vi cua viet*.