Perhaps you should try some spelling variations:
cam truc » cau truc, nam truc, lam truoc
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
truc va » thuc va, thuc vat, trung va
vi luu » vi lua
vi cuu » vinh cuu
va don » va dong, va doc, va do
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky ((nang xa) or (nang ma)) hoi. hieu va cam truc va don ((vi cuu) OR (vi luu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (nang ma)) hoi. hieu va cam truc va don ((vi cuu) OR (vi luu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky ((nang xa) or (nang ma)) hoi. hieu va cam truc va don ((vi cuu) OR (vi luu)) tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (nang ma)) hoi. hieu va cam truc va don ((vi cuu) OR (vi luu)) tre*.