Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
doc sach » hoc sach, toc sach, nuoc sach
hieu voi » hieu moi, lieu voi, hieu loi
hieu vi » hieu va, hieu ve, hien vi
sach ty » sach y, sach tu, sach thu
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
ty nang » ky nang, ty xang, ty hang
vai cua » hai cua, lai cua, bai cua
x hoi » xa hoi, o hoi, x ho

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 ty nang x hoi. ((hieu vi) OR (hieu voi)) pham thuc va hanh ((vai cua) or (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty nang x hoi. ((hieu vi) OR (hieu voi)) pham thuc va hanh ((vai cua) OR (dai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty nang x hoi. ((hieu vi) OR (hieu voi)) pham thuc va hanh ((vai cua) or (dai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: doc sach ty nang x hoi. ((hieu vi) OR (hieu voi)) pham thuc va hanh ((vai cua) or (dai cua)) triet*.