Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
tham thuc » nham thuc, pham thuc, tam thuc
hieu van » hieu va, thien van, lieu va
van tham » van thanh, van tuan, van chat
thuc day » thuc dan, thuc vat
thanh vi » hanh vi, thanh va, thanh ve
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo

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 ky nang cao hoi. hieu van tham thuc day thanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang cao hoi. hieu van tham thuc day thanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang cao hoi. hieu van tham thuc day thanh vi ((cua tre) or (cuu tre))*.