Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
thanh lap » thanh san, phan lap, thanh hai
dau thuc » dan thuc, dai thuc, dam thuc
hanh lam » hanh kem, hanh va, dinh lam
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, dua tren
te sach » toc sach
va dau » va dao
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ma hoi. hieu va dau thuc vat ((hanh lam) OR (thanh lap)) ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ma hoi. hieu va dau thuc vat ((hanh lam) OR (thanh lap)) ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ma hoi. hieu va dau thuc vat ((hanh lam) OR (thanh lap)) ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ma hoi. hieu va dau thuc vat ((hanh lam) OR (thanh lap)) ((cua tre) or (cua triet))*.