Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu he » hieu ve, hiem he, hieu hien
tu sach » thu sach, su sach, te sach
hieu le » hieu ve, hieu ly, tieu le
ky dang » ky danh
ha hoi » hoa hoi, ha noi, xa hoi
vi va » vi van, vai va, vu va

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 dang) or (ky nang)) ha hoi. ((hieu le) OR (hieu he)) nam thuc va hanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky nang)) ha hoi. ((hieu le) OR (hieu he)) nam thuc va hanh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky nang)) ha hoi. ((hieu le) OR (hieu he)) nam thuc va hanh vi va triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky nang)) ha hoi. ((hieu le) OR (hieu he)) nam thuc va hanh vi va triet*.