Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
ang xa » mang xa, dang xay, hoang xa
cac su » cach su, cac sau, cac du
cuc te » cua te, cuc thue, cuc tieu
su va » su van, tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) y ((ang xa) or (lang xa)) hoi. hieu va cac su va hanh tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) y ((ang xa) OR (lang xa)) hoi. hieu va cac su va hanh tai cuc te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) y ((ang xa) or (lang xa)) hoi. hieu va cac su va hanh tai cuc te*.