Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
sach thu » sach thue, sach thieu, sach tham
hanh va » hang va, hanh vi
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
sach ty » sach y, sach tu, xach tay
tang ma » mang may, tang van
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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) or (sach thu)) tang ma hoi. hieu vu cham duc va ((hanh va) or (thanh san)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sach ty) OR (sach thu)) tang ma hoi. hieu vu cham duc va ((hanh va) OR (thanh san)) cua tre.
• Adding a wildcard symbol may retrieve word variants: so ((sach ty) or (sach thu)) tang ma hoi. hieu vu cham duc va ((hanh va) or (thanh san)) cua tre*.