Perhaps you should try some spelling variations:
duy nhanh » duy khanh, day nhanh, duy anh
cam thuc » am thuc, nam thuc, cam thu
dao hanh » dao thanh, dang hanh, ban hanh
sach ky » sac ky, sach y, sach ty
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cuu tre, cua triet
hieu va » hieu qua
di cua » dai cua, doi cua, de cua
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: vu sach ky nang x hoi. ((hieu va) OR (lieu va)) cam thuc ((dao hanh) or (duy nhanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. ((hieu va) OR (lieu va)) cam thuc ((dao hanh) OR (duy nhanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. ((hieu va) OR (lieu va)) cam thuc ((dao hanh) or (duy nhanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. ((hieu va) OR (lieu va)) cam thuc ((dao hanh) or (duy nhanh)) di cua tre*.