Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
cam thuc » am thuc, cam thu, can thuc
nang mai » nang ma, nang tai, lang mai
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va thanh, va danh
so sach » so sanh, bo sach, co sach
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu van
hieu va » lieu va, hieu qua
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach v nang mai hoi. ((hieu ve) OR (hieu va)) ((cam thuc) or (nam thuc)) va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v nang mai hoi. ((hieu ve) OR (hieu va)) ((cam thuc) OR (nam thuc)) va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach v nang mai hoi. ((hieu ve) OR (hieu va)) ((cam thuc) or (nam thuc)) va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: so sach v nang mai hoi. ((hieu ve) OR (hieu va)) ((cam thuc) or (nam thuc)) va hanh vi cua viet*.