Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
cua tre » cua te, cuu tre, cua triet
va danh » va dinh, va dan, dia danh
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, ban hanh
vi cua » vai cua, di cua
ma hoi » mai hoi, xa hoi, ma hoa
ve nam » he nam, va nam, le nam

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu bach) or (toc sach)) ky tang ma hoi. hieu ve nam thuc ((va hanh) or (va danh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu bach) OR (toc sach)) ky tang ma hoi. hieu ve nam thuc ((va hanh) OR (va danh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((vu bach) or (toc sach)) ky tang ma hoi. hieu ve nam thuc ((va hanh) or (va danh)) vi cua tre*.