Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh va » thanh van, hanh va, thanh ha
cham duc » pham duc, cham soc, pham duy
sach ky » sach y, sach ty, sach kem
duc ban » duc tan, duc van, dua ban
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
hoa hoi » khoa hoi, hoa hoc, hoa doi
cua tre » cua te, cuu tre, cua triet
ha hoi » ha noi, xa hoi, va hoi
sac ky » cac ky, sai ky
va cua » va chua, via cua, ca cua

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 ky) or (sac ky)) tang ((ha hoi) OR (hoa hoi)). hieu ve cham duc ban thanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) tang ((ha hoi) OR (hoa hoi)). hieu ve cham duc ban thanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) tang ((ha hoi) OR (hoa hoi)). hieu ve cham duc ban thanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) tang ((ha hoi) OR (hoa hoi)). hieu ve cham duc ban thanh va cua tre*.