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
thu sach » tu sach, thuat sach, thuoc sach
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
sach ky » sac ky, sach y, sach ty
cao hoc » co hoc, cho hoc, chat hoc
cao hoi » cau hoi, co hoi, tao hoi
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 nang ((cao hoi) OR (cao hoc)). 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 nang ((cao hoi) OR (cao hoc)). hieu ve pham thuc ((day hanh) or (day nhanh)) di cua te~".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((cao hoi) OR (cao hoc)). hieu ve pham thuc ((day hanh) or (day nhanh)) di cua te*.