Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau theo » cau thi, cau tao
lang xa » dang xay, lang van
lang ha » long ha
sach ky » sac ky, sach y, sach ty
dao tai » dao thai, dao tao, cao tai
tai cau » tai cac, tai cao
hieu va » hieu qua
thu va » thuc va, thue va, tu va
va dao » ca dao

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 ((lang xa) or (lang ha)) hoi. ((hieu va) or (lieu va)) nam thu va dao tai cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((lang xa) OR (lang ha)) hoi. ((hieu va) OR (lieu va)) nam thu va dao tai cau theo.
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((lang xa) or (lang ha)) hoi. ((hieu va) or (lieu va)) nam thu va dao tai cau theo*.