Perhaps you should try some spelling variations:
ban hanh » ban hang
te sach » toc sach
va tinh » may tinh
van hac » van hoc, van ha, van hai
van cac » van cau, van bac, dan cac
cau tre » cau tren, cau treo, cau tra
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
da cau » dat cau, va cau
x hoi » xa hoi, o hoi, x ho

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 hoi. hieu ((van cac) OR (van hac)) duc ((ban hanh) or (va tinh)) da cau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v nang x hoi. hieu ((van cac) OR (van hac)) duc ((ban hanh) OR (va tinh)) da cau tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach v nang x hoi. hieu ((van cac) OR (van hac)) duc ((ban hanh) or (va tinh)) da cau tre".
• Adding a wildcard symbol may retrieve word variants: te sach v nang x hoi. hieu ((van cac) OR (van hac)) duc ((ban hanh) or (va tinh)) da cau tre*.