Perhaps you should try some spelling variations:
su sach » so sach, vu sach
va danh » va dinh, va hanh, dia danh
sach ky » sac ky, sach y, sach ty
hieu he » hieu ve, hiem he, hieu le
sang ma » tang ma, nang ma, sang tao
cuu tre » cua tre, cau tren, cau treo
he nam » ha nam, nghe nam
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((sang ma) or (nang cao)) hoi. hieu he nam thu ((va danh) OR (va dan)) sai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((sang ma) OR (nang cao)) hoi. hieu he nam thu ((va danh) OR (va dan)) sai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((sang ma) or (nang cao)) hoi. hieu he nam thu ((va danh) OR (va dan)) sai cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((sang ma) or (nang cao)) hoi. hieu he nam thu ((va danh) OR (va dan)) sai cuu tre*.