Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cham luc » cham soc, nhan luc, cham cuu
hanh ve » hanh va, hanh kem
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
nang xa » lang xa, nang ma, mang xa
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
tu sac » tu sach, tu cac, tu san

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

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