Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
ve triet » va trien, su triet
su sach » so sach, vu sach
nang xa » lang xa, mang xa, ang xa
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
ve cau » ke cau, va cau, ve cac
vi ve » va ve, gi ve, ve ve

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y ((((nang xa) OR (nang x))) or (nang ma)) hoi. hieu ve cau thuc va hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((((nang xa) OR (nang x))) OR (nang ma)) hoi. hieu ve cau thuc va hanh vi ve triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((((nang xa) OR (nang x))) or (nang ma)) hoi. hieu ve cau thuc va hanh vi ve triet*".