Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
tai cau » tai cao
tai cac » tai cuc
va nam » van nam, va nay
thu va » thuc va, thue va, tu va
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: toc sach ky tang xa hoi. hieu ((va nam) OR (ha nam)) thu va dan ((tai cau) or (tai cac)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky tang xa hoi. hieu ((va nam) OR (ha nam)) thu va dan ((tai cau) OR (tai cac)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky tang xa hoi. hieu ((va nam) OR (ha nam)) thu va dan ((tai cau) or (tai cac)) treo".
• Adding a wildcard symbol may retrieve word variants: toc sach ky tang xa hoi. hieu ((va nam) OR (ha nam)) thu va dan ((tai cau) or (tai cac)) treo*.