Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vi » hanh vi, thanh va, thanh ve
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty lang » tay lang, ty xang, ty hang
lang ha » long ha
van cam » van lam, van cau, van dam
hoc ban » hoc bang, hoc dan, hoc bai
ha hoi » hoa hoi, ha noi, xa hoi
vi cau » va cau, ve cau, di cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty lang ha hoi. hieu ((van cam) or (van nam)) hoc ban thanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty lang ha hoi. hieu ((van cam) OR (van nam)) hoc ban thanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: su sach ty lang ha hoi. hieu ((van cam) or (van nam)) hoc ban thanh vi cau tren*.