Perhaps you should try some spelling variations:
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va
cam tuc » cam xuc, cam tu, nam thuc
va hanh » van hanh, va thanh, va danh
ca tren » cau tren, cu tren, la tren
tu dan » tuc dan, tu ban, cu dan
dan ky » van ky
tuc va » thuc va, truc va, tuc xa
kem ca » kem cd

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu dan ky ((nang xa) or (nang x)) hoi. ((hieu va) OR (hieu qua)) cam tuc va hanh kem ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu dan ky ((nang xa) OR (nang x)) hoi. ((hieu va) OR (hieu qua)) cam tuc va hanh kem ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu dan ky ((nang xa) or (nang x)) hoi. ((hieu va) OR (hieu qua)) cam tuc va hanh kem ca tren".
• Adding a wildcard symbol may retrieve word variants: tu dan ky ((nang xa) or (nang x)) hoi. ((hieu va) OR (hieu qua)) cam tuc va hanh kem ca tren*.