Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
su sach » so sach, vu sach
tai cua » thai cua, tai cuc, tri cua
duc ban » duc tan, duc van, dua ban
luc ban » cuc ban, luc bat, luc van
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 5 tang
7 tang » 6 tang

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 ((y tang) OR (7 tang)) ma hoa. hieu va chat ((luc ban) or (duc ban)) thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y tang) OR (7 tang)) ma hoa. hieu va chat ((luc ban) OR (duc ban)) thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y tang) OR (7 tang)) ma hoa. hieu va chat ((luc ban) or (duc ban)) thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((y tang) OR (7 tang)) ma hoa. hieu va chat ((luc ban) or (duc ban)) thanh tai cua tre*.