Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hanh tai » thanh tai, hang tai, han tai
sach ty » sach tu, sach thu, xach tay
nang du » nang tu, nang luc, nang doc
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
du hoi » du hoc, lu hoi, di hoi
ve nam » he nam, va nam, le nam

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) or (sach ty)) nang du hoi. hieu ve nam thuc va hanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach y) OR (sach ty)) nang du hoi. hieu ve nam thuc va hanh tai cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach y) or (sach ty)) nang du hoi. hieu ve nam thuc va hanh tai cua tre*.