Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban hang » ngan hang
nhan luc » nang luc
ve triet » va trien, su triet
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
luc ban » duc ban, cuc ban, luc bat
nang xa » nang x, lang xa, mang xa
hang vi » hang va, hanh vi, hang di
va nhan » van nhan, ca nhan, va phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((nang xa) or (nang ma)) hoi. hieu va nhan luc ban hang vi ((va thiet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((nang xa) OR (nang ma)) hoi. hieu va nhan luc ban hang vi ((va thiet) OR (ve triet)).
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((nang xa) or (nang ma)) hoi. hieu va nhan luc ban hang vi ((va thiet) or (ve triet))*.