Perhaps you should try some spelling variations:
duy nhanh » duy khanh, day nhanh, duy anh
day hanh » day nhanh, day thanh, dao hanh
cam thuc » am thuc, nam thuc, cam thu
cuu tre » cau tren, cau treo
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cua tre » cua te, cua triet, dua tren
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, o hoi, x ho

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

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