Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
khoa hoi » khoan hoi, khoa hoc, khoa doi
va hanh » van hanh, va thanh, va danh
cao xuc » cam xuc, cao duc, cao suc
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
hoa hoi » hoa hoc, hoa doi, hoc hoi
ky dang » ky nang, ky danh
va dan » ca dan, va dao, va dau
di cua » dai cua, doi cua, de cua
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ky dang ((hoa hoi) or (khoa hoi)). hieu va cao xuc ((va hanh) or (va dan)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky dang ((hoa hoi) OR (khoa hoi)). hieu va cao xuc ((va hanh) OR (va dan)) di cua tre.
• Adding a wildcard symbol may retrieve word variants: thuoc sach ky dang ((hoa hoi) or (khoa hoi)). hieu va cao xuc ((va hanh) or (va dan)) di cua tre*.