Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, phan duc
pham duy » pham duc
lang van » dang van, tang van, hoang van
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
bo sach » co sach, hoc sach
hieu va » lieu va, hieu qua
lang ha » long ha
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: bo sach y ((lang van) or (lang ha)) hoi. hieu va ((cham duc) OR (pham duy)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach y ((lang van) OR (lang ha)) hoi. hieu va ((cham duc) OR (pham duy)) va hanh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach y ((lang van) or (lang ha)) hoi. hieu va ((cham duc) OR (pham duy)) va hanh vai cua tre*".