Perhaps you should try some spelling variations:
vien sach » vien bach, dien sach, viet sach
hieu vien » hieu hien, hieu viec, thieu nien
ban hang » ngan hang
va hanh » van hanh, va thanh, va danh
sach ty » sach y, sach tu, sach thu
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ty ((nang xa) OR (nang ma)) hoi. hieu vien sach dung ((ban hang) or (va hanh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((nang xa) OR (nang ma)) hoi. hieu vien sach dung ((ban hang) OR (va hanh)) de cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((nang xa) OR (nang ma)) hoi. hieu vien sach dung ((ban hang) or (va hanh)) de cua tre*".