Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
vat hanh » vat thanh, van hanh, va hanh
cua tre » cua te, cua triet, dua tren
ve tham » va tham, ve cham, vi tham
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
cuu tre » cau tren, cau treo
nang co » nang cao, nang doc, nang noi
co hoi » co hoc, co loi
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) OR (sac ky)) nang co hoi. hieu ve tham thuc vat hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) nang co hoi. hieu ve tham thuc vat hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sac ky)) nang co hoi. hieu ve tham thuc vat hanh vi ((cua tre) or (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sac ky)) nang co hoi. hieu ve tham thuc vat hanh vi ((cua tre) or (cuu tre))*.