Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hanh lai » hanh lam, hanh tai, thanh lap
phat day » phap day, phan day, phan dau
van phat » va phat, van chat, van phan
hieu van » hieu va, thien van, lieu va
lai cua » dai cua, hai cua, lai chau
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, 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: ((toc sach) or (hoc sach)) ty xang ((ma hoi) OR (ma hoa)). hieu van phat day va hanh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ty xang ((ma hoi) OR (ma hoa)). hieu van phat day va hanh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc sach)) ty xang ((ma hoi) OR (ma hoa)). hieu van phat day va hanh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ty xang ((ma hoi) OR (ma hoa)). hieu van phat day va hanh lai cua tre*.