Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va vanh » va van, va danh, va hanh
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: tu sach ky nang xa hoi. hieu ve cau thuc va vanh ((dai va) OR (mai va)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang xa hoi. hieu ve cau thuc va vanh ((dai va) OR (mai va)) triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang xa hoi. hieu ve cau thuc va vanh ((dai va) OR (mai va)) triet*.