Perhaps you should try some spelling variations:
nham thuc » nhan thuc, nham thu, pham thuc
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
so sach » so sanh, bo sach, co sach
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
vi cua » vai cua, di cua

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: ((so sach) OR (toc sach)) ky nang ma hoi. hieu va ((nham thuc) OR (nam thuc)) va hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (toc sach)) ky nang ma hoi. hieu va ((nham thuc) OR (nam thuc)) va hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (toc sach)) ky nang ma hoi. hieu va ((nham thuc) OR (nam thuc)) va hanh vi cua tre*.