Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tay tang » tay lang, tay trung, tay quang
cham duc » pham duc, cham soc, pham duy
su sach » so sach, vu sach
vu cham » va cham, vu kham, tu cham
lam cua » nam cua, lam chat
va hanh » va thanh, va danh, ban hanh
hieu vu » hieu va, hieu ve, hieu su
ty tang » ty xang, ty hang, ky tang
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: su sach ((ty tang) OR (tay tang)) ma hoi. hieu vu cham duc ((va hanh) or (van hanh)) lam cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty tang) OR (tay tang)) ma hoi. hieu vu cham duc ((va hanh) OR (van hanh)) lam cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty tang) OR (tay tang)) ma hoi. hieu vu cham duc ((va hanh) or (van hanh)) lam cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty tang) OR (tay tang)) ma hoi. hieu vu cham duc ((va hanh) or (van hanh)) lam cua tre*.