Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cam thuc » am thuc, nam thuc, can thuc
day hanh » day nhanh, day thanh, dao hanh
hanh di » hanh vi, hanh de, hang di
cam thu » nam thu, cac thu, ca thu
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
hieu ve » hieu van
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
di cua » dai cua, doi cua, de cua

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: su sach v nang x ho. ((hieu ve) OR (hieu va)) ((cam thuc) OR (cam thu)) day hanh di cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach v nang x ho. ((hieu ve) or (hieu va)) ((cam thuc) OR (cam thu)) day hanh di cua triet~".
• Adding a wildcard symbol may retrieve word variants: su sach v nang x ho. ((hieu ve) or (hieu va)) ((cam thuc) OR (cam thu)) day hanh di cua triet*.