Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
hanh lam » thanh lap, hanh kem, hanh va
su sach » so sach, vu sach
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
va hanh » van hanh, va thanh, va danh
lam cua » nam cua, lam chat
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 7 tang
ma hoi » mai hoi, ma hoa, me hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y tang ((ma hoi) OR (xa hoi)). hieu vu cham duc va hanh lam cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y tang ((ma hoi) OR (xa hoi)). hieu vu cham duc va hanh lam cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y tang ((ma hoi) OR (xa hoi)). hieu vu cham duc va hanh lam cua tre*.