Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
doanh va » doan va, doanh tai, doanh cua
va doanh » van doanh, vay doanh, va danh
cap nuoc » dat nuoc
hieu ve » hieu va, hieu van
lang xa » dang xay, lang van
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
sach o » sach lo, sac o, sach y
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach o ((lang xa) or (lang ha)) hoi. hieu ve ((cap nuoc) or (hoc nuoc)) va doanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach o ((lang xa) OR (lang ha)) hoi. hieu ve ((cap nuoc) OR (hoc nuoc)) va doanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach o ((lang xa) or (lang ha)) hoi. hieu ve ((cap nuoc) or (hoc nuoc)) va doanh va cua tre*.