Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
luc ngan » luc nganh, luc nhan, luat ngan
hieu van » hieu va, thien van, lieu va
sach ty » sach y, sach thu, xach tay
hang vi » hang va, hanh vi, hang di
cam luc » cam xuc, cau luc
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach uu
vi cau » va cau, ve cau, di cau

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 ty) OR (sach tu)) ((nang xa) or (nang cao)) hoi. hieu van cam luc ngan hang vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach tu)) ((nang xa) OR (nang cao)) hoi. hieu van cam luc ngan hang vi cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach tu)) ((nang xa) or (nang cao)) hoi. hieu van cam luc ngan hang vi cau tren".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach tu)) ((nang xa) or (nang cao)) hoi. hieu van cam luc ngan hang vi cau tren*.