Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
cau tren » cu tren, dau tren, ca tren
dua tren » dung tren
thuc day » thuc dan, thuc vat
day hanh » day nhanh, day thanh, dao hanh
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
nang co » nang cao, nang doc, nang noi
tu sach » thu sach, su sach, te sach
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 pham thuc day hanh vi ((((cua tre) or (dua tren))) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang co hoi. hieu ve pham thuc day hanh vi ((((cua tre) OR (dua tren))) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang co hoi. hieu ve pham thuc day hanh vi ((((cua tre) or (dua tren))) or (cau tren))*.