Perhaps you should try some spelling variations:
hieu quan » hieu qua, lieu quan, thien quan
hanh dieu » han dieu, hinh dieu, hoang dieu
dieu cua » dieu tra
nam thuc » nam thuoc, am thuc, nam thu
quan nam » quang nam, xuan nam, quan am
nang hoa » nang hoat, hang hoa, nang hoc
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
tu sach » thu sach, te sach, vu sach
su sach » so sach, vu sach
tu cach » tu cac
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: ((((tu sach) or (tu cach))) or (su sach)) ky nang hoa hoc. hieu quan nam thuc va hanh dieu cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((tu sach) OR (tu cach))) OR (su sach)) ky nang hoa hoc. hieu quan nam thuc va hanh dieu cua tre.
• Adding a wildcard symbol may retrieve word variants: ((((tu sach) or (tu cach))) or (su sach)) ky nang hoa hoc. hieu quan nam thuc va hanh dieu cua tre*.