Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
hanh lam » thanh lap, hanh kem, hanh va
so sach » so sanh, co sach, hoc sach
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
may hoi » may thoi, tay hoi, mai hoi
ty mang » ty xang, ty hang, tin mang
bo sach » co sach, hoc sach
cua tre » cua te, cuu tre, cua triet

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) OR (bo sach)) ty mang may hoi. hieu vu cham duc va ((hanh lam) or (thanh san)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (bo sach)) ty mang may hoi. hieu vu cham duc va ((hanh lam) OR (thanh san)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (bo sach)) ty mang may hoi. hieu vu cham duc va ((hanh lam) or (thanh san)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (bo sach)) ty mang may hoi. hieu vu cham duc va ((hanh lam) or (thanh san)) cua tre*.