Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
cau tren » cu tren, dau tren, ca tren
xang xa » lang xa, mang xa, ang xa
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
duc gia » quoc gia
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: ((te sach) or (toc sach)) ty xang xa hoi. hieu van cam duc gia thanh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty xang xa hoi. hieu van cam duc gia thanh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty xang xa hoi. hieu van cam duc gia thanh vi cau tren*.