Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
day hanh » day nhanh, day thanh, dao hanh
dua tren » dung tren
thuc day » thuc dan, thuc vat
cua tre » cua te, cua triet, cua thep
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
ve tham » va tham, ve cham, vi tham
hieu ve » hieu va, hieu van
nang co » nang cao, nang doc, nang noi
cuu tre » cau tren, cau treo
co hoi » co hoc, co loi

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