Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hanh tai » thanh tai, hang tai, han tai
hieu van » hieu va, thien van, hieu ve
thuc va » thuc vat, thuc dan, thuc day
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
dang ma » dang mau, dang mam, dang mat
sac ky » cac ky, sai ky
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sac ky dang ma hoa. ((hieu van) OR (lieu va)) nam thuc va ((hanh va) or (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang ma hoa. ((hieu van) OR (lieu va)) nam thuc va ((hanh va) OR (hanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky dang ma hoa. ((hieu van) OR (lieu va)) nam thuc va ((hanh va) or (hanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky dang ma hoa. ((hieu van) OR (lieu va)) nam thuc va ((hanh va) or (hanh tai)) cua tre*.