Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
cua triet » cua viet, su triet, va triet
doc sach » hoc sach, toc sach, nuoc sach
hieu voi » hieu moi, lieu voi, hieu loi
hanh lai » hanh lam, hanh tai, thanh lap
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
lai cua » dai cua, hai cua, lai chau
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky nang ma hoi. ((hieu voi) or (hieu ve)) pham thuc va hanh lai cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky nang ma hoi. ((hieu voi) OR (hieu ve)) pham thuc va hanh lai cua triet.
• Adding a wildcard symbol may retrieve word variants: doc sach ky nang ma hoi. ((hieu voi) or (hieu ve)) pham thuc va hanh lai cua triet*.