Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thanh hai » thanh phan, thanh hoa, thanh san
ban thanh » ban hanh, ban hang
nang mai » nang ma, nang tai, lang mai
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cua triet, dua tren
hieu ve » hieu va, hieu van
ve chay » ve chat, de chay, ve cham
sach ty » sach y, sach tu, sach thu
mai hoi » mai khoi, dai hoi, lai hoi
cuu tre » cau tren, cau treo

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach ty) or (sach thue)) nang mai hoi. hieu ve chay dua ban thanh hai ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thue)) nang mai hoi. hieu ve chay dua ban thanh hai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) or (sach thue)) nang mai hoi. hieu ve chay dua ban thanh hai ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) or (sach thue)) nang mai hoi. hieu ve chay dua ban thanh hai ((cua tre) OR (cuu tre))*.