Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
va danh » va dinh, va dan, va hanh
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
hoa hoi » khoa hoi, hoa hoc, hoa doi
ty dong » tay dong, ly dong, ty nong
vi cua » vai cua, di cua
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ty dong) OR (tu dong)) hoa hoi. hieu va cam xuc ((ban hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ty dong) OR (tu dong)) hoa hoi. hieu va cam xuc ((ban hanh) OR (va danh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ty dong) OR (tu dong)) hoa hoi. hieu va cam xuc ((ban hanh) or (va danh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ty dong) OR (tu dong)) hoa hoi. hieu va cam xuc ((ban hanh) or (va danh)) vi cua tre*.