Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
xanh di » vanh dai, xanh tai
danh di » danh du, danh dien, danh gia
ve pham » vi pham, v pham, ve phan
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa

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: ((te sach) OR (toc sach)) ky nang ma hoi. hieu ve pham duc va ((danh di) OR (xanh di)) cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky nang ma hoi. hieu ve pham duc va ((danh di) OR (xanh di)) cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang ma hoi. hieu ve pham duc va ((danh di) OR (xanh di)) cua tre*.