Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
cam thuc » am thuc, nam thuc, can thuc
dao hanh » dao thanh, dang hanh, ban hanh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cam thu » nam thu, cac thu, ca thu
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua

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 ho. hieu va ((cam thuc) OR (cam thu)) ((dao hanh) or (day nhanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x ho. hieu va ((cam thuc) OR (cam thu)) ((dao hanh) OR (day nhanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x ho. hieu va ((cam thuc) OR (cam thu)) ((dao hanh) or (day nhanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x ho. hieu va ((cam thuc) OR (cam thu)) ((dao hanh) or (day nhanh)) di cua tre*.