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

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