Perhaps you should try some spelling variations:
nhan luc » nang luc
ban hanh » ban hang
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va nhan » van nhan, ca nhan, va phan
luc ban » duc ban, cuc ban, luc bat

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 ky ((nang ma) or (nang x)) hoi. hieu va nhan luc ban hanh vi ((va thiet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (nang x)) hoi. hieu va nhan luc ban hanh vi ((va thiet) OR (su triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (nang x)) hoi. hieu va nhan luc ban hanh vi ((va thiet) or (su triet))*.