Perhaps you should try some spelling variations:
ban hanh » ban hang
hieu van » hieu va, thien van, lieu va
te sach » toc sach
van cac » van hac, van cau, van bac
cac duc » cac du, cao duc, cac dac
cau tra » ca tra, cau ra, cau truc
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
di cau » da cau, diem cau

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 v nang x ho. hieu van cac duc ((ban hanh) or (gia thanh)) di cau tra~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v nang x ho. hieu van cac duc ((ban hanh) OR (gia thanh)) di cau tra.
• Adding a wildcard symbol may retrieve word variants: te sach v nang x ho. hieu van cac duc ((ban hanh) or (gia thanh)) di cau tra*.