Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
day nhanh » day thanh, duy nhanh, dac nhan
day hanh » day thanh, dao hanh, day manh
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
sach ky » sach y, sach ty, sach kem
cao hoi » cau hoi, co hoi, cao hoc
sac ky » cac ky, sai ky
di cua » dai cua, doi cua, de cua
cua te » cua tu

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

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