Perhaps you should try some spelling variations:
duy nhanh » duy khanh, day nhanh, duy anh
cua viet » ca viet, hoa viet, cua vat
cam thuc » am thuc, nam thuc, cam thu
dao hanh » dao thanh, dang hanh, ban hanh
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
vu sach » vu bach, su sach, vu khach
va cam » va cham, va cac, va cao
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang o hoi. hieu va cam thuc ((dao hanh) or (duy nhanh)) di ((cua tre) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang o hoi. hieu va cam thuc ((dao hanh) OR (duy nhanh)) di ((cua tre) OR (cua viet)).
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang o hoi. hieu va cam thuc ((dao hanh) or (duy nhanh)) di ((cua tre) or (cua viet))*.