Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
van hanh » van thanh, ban hanh, van anh
tang van » dang van, hoang van, trong van
su sach » so sach, vu sach
lam cua » nam cua, lam chat
va hanh » va thanh, va danh, ban hanh
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
tang xa » trang xa, tang ma, lang xa
cua tre » cua te, cuu tre, cua triet

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 xa) or (tang van)) 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 y ((tang xa) OR (tang van)) 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 y ((tang xa) or (tang van)) hoi. hieu vu cham duc ((va hanh) OR (van hanh)) lam cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach y ((tang xa) or (tang van)) hoi. hieu vu cham duc ((va hanh) OR (van hanh)) lam cua tre*.