Perhaps you should try some spelling variations:
nang hoat » trang hoat, hang hoa, nang suat
hanh dieu » han dieu, hinh dieu, hoang dieu
dieu cua » dieu tra
nang hoa » hang hoa, nang hoc, nang ho
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
va nam » van nam, ha nam, va nay

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 (su sach)) ky ((nang hoa) OR (nang hoat)) hoc. hieu va nam thuc va hanh dieu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky ((nang hoa) OR (nang hoat)) hoc. hieu va nam thuc va hanh dieu cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky ((nang hoa) OR (nang hoat)) hoc. hieu va nam thuc va hanh dieu cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky ((nang hoa) OR (nang hoat)) hoc. hieu va nam thuc va hanh dieu cua tre*.