Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
hang ca » hang va, nang cao, hang tai
hang xa » hoang xa, hang va, lang xa
bo sach » co sach, hoc sach

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (bo sach)) ty ((hang xa) or (hang ca)) hoi. hieu ve cham thuc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (bo sach)) ty ((hang xa) OR (hang ca)) hoi. hieu ve cham thuc va hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (bo sach)) ty ((hang xa) or (hang ca)) hoi. hieu ve cham thuc va hanh vai cua tre*.