Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
doc sach » hoc sach, toc sach, nuoc sach
su triet » su viet, ve triet
hanh san » thanh san, khach san, thanh son
sach ty » sach y, sach tu, sach thu
hanh va » hang va, hanh vi
thuc va » thuc vat, thuc dan, thuc day
hieu vi » hieu voi, hieu va, hieu ve
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
su tien » su kien, su hien, tu tieng
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 ty nang ma hoi. hieu vi pham thuc va ((hanh san) or (hanh va)) ((su triet) OR (su tien))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ty nang ma hoi. hieu vi pham thuc va ((hanh san) OR (hanh va)) ((su triet) OR (su tien)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ty nang ma hoi. hieu vi pham thuc va ((hanh san) or (hanh va)) ((su triet) OR (su tien))".
• Adding a wildcard symbol may retrieve word variants: doc sach ty nang ma hoi. hieu vi pham thuc va ((hanh san) or (hanh va)) ((su triet) OR (su tien))*.