Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cham duc » pham duc, cham soc, pham duy
su sach » so sach
lam cua » nam cua, lam chat
va hanh » va thanh, va danh, ban hanh
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
tang ma » mang may, tang van
ty tang » tay tang, ty xang, ty hang
vu sach » vu bach, vu khach
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) OR (vu sach)) ty 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) OR (vu sach)) ty 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) OR (vu sach)) ty 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) OR (vu sach)) ty tang ma hoi. hieu vu cham duc ((va hanh) or (van hanh)) lam cua tre*.