Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
cua triet » cua viet, va triet
hanh tai » thanh tai, hang tai, han tai
doc sach » hoc sach, toc sach, nuoc sach
su triet » su viet, su tien, ve triet
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
ty nang » ty xang, ty hang, ly nang

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