Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu van
hieu va » lieu va, hieu qua
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
vi va » vai va, vu va, bi va

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

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