Perhaps you should try some spelling variations:
hieu san » hieu van, hieu sau, chieu sang
san chay » san pham, van chat, dan chan
hanh tai » thanh tai, hang tai, han tai
kho tang » cao tang
ban hanh » ban hang
cua tre » cuu tre, cua triet, dua tren
dua ban » dia ban, cua ban, qua ban
tu sach » thu sach, su sach, te sach
ky tang » ky nang, ky dang, ky trong
cua te » cua tu

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 ((ky tang) OR (kho tang)) ma hoa. hieu san chay dua ban hanh tai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (kho tang)) ma hoa. hieu san chay dua ban hanh tai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky tang) OR (kho tang)) ma hoa. hieu san chay dua ban hanh tai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky tang) OR (kho tang)) ma hoa. hieu san chay dua ban hanh tai ((cua tre) or (cua te))*.