Perhaps you should try some spelling variations:
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
cuu tre » cua tre, cau tren, cau treo
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
va cau » van cau, va cac, va dau
va don » va dong, va doc, va do
vi cuu » vi luu, vinh cuu

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 cau truc va don vi cuu 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 cau truc va don vi cuu tre.
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (nang ma)) hoi. hieu va cau truc va don vi cuu tre*.