Perhaps you should try some spelling variations:
sach tham » sach nha
sach thu » sach thue, sach thieu, cach thuc
hanh lam » thanh lap, hanh kem, hanh va
hoc cac » hoc cao
hoc can » hoc dan, hoc cao, hoc phan
lam phu » lam chu, cam phu, am phu
hieu ve » hieu va, hieu van
hang x » nang x, hoang xa, chang xu
ve cau » ke cau, va cau, ve cac
tho » thoi, theo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach thu) or (sach tham)) hang x ho. hieu ve cau ((hoc can) OR (hoc cac)) hanh lam phu tho~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach thu) OR (sach tham)) hang x ho. hieu ve cau ((hoc can) OR (hoc cac)) hanh lam phu tho.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach thu) or (sach tham)) hang x ho. hieu ve cau ((hoc can) OR (hoc cac)) hanh lam phu tho".
• Adding a wildcard symbol may retrieve word variants: tu ((sach thu) or (sach tham)) hang x ho. hieu ve cau ((hoc can) OR (hoc cac)) hanh lam phu tho*.