Perhaps you should try some spelling variations:
dieu hoa » dien hoa, tieu hoa, hieu hoa
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
nam thuc » nam thuoc, am thuc, nam thu
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
hieu ha » hieu hoa, hieu va, hieu ca
lang ha » long ha
ky lang » ky nang, ky dang, ky tang
ha hoi » hoa hoi, ha noi, xa hoi

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 (thuat toan)) ky lang ha hoi. ((hieu ha) or (dieu hoa)) nam thuc van hanh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thuat toan)) ky lang ha hoi. ((hieu ha) OR (dieu hoa)) nam thuc van hanh dai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thuat toan)) ky lang ha hoi. ((hieu ha) or (dieu hoa)) nam thuc van hanh dai cua tre*.