Perhaps you should try some spelling variations:
sach bai » sach dao, cac bai, sach xa
ban hang » ngan hang
hieu van » hieu va, thien van, lieu va
sach thi » sach thu, sach tai, sach thieu
luc ban » duc ban, cuc ban, luc bat
hang vi » hang va, hanh vi, hang di
van cam » van nam, van lam, van cau
cam luc » cam xuc, cau luc
nang xa » nang x, lang xa, nang ma
cua tu » cua tuc, cua cu, cua te
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach thi) or (sach bai)) nang xa hoi. hieu van cam luc ban hang vi ((cua tu) OR (cua su))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach thi) OR (sach bai)) nang xa hoi. hieu van cam luc ban hang vi ((cua tu) OR (cua su)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach thi) or (sach bai)) nang xa hoi. hieu van cam luc ban hang vi ((cua tu) OR (cua su))".
• Adding a wildcard symbol may retrieve word variants: te ((sach thi) or (sach bai)) nang xa hoi. hieu van cam luc ban hang vi ((cua tu) OR (cua su))*.