Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
su sach » so sach, vu sach
sang ma » tang ma, nang ma, sang tao
nang xa » nang x, lang xa, nang ma
vai va » mai va, hai va, lai va
dai va » mai va
ve cau » ke cau, va cau, ve cac

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 (sang ma)) hoi. hieu ve cau thuc va hanh ((vai va) OR (dai va)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y ((nang xa) OR (sang ma)) hoi. hieu ve cau thuc va hanh ((vai va) OR (dai va)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((nang xa) or (sang ma)) hoi. hieu ve cau thuc va hanh ((vai va) OR (dai va)) triet*".