Perhaps you should try some spelling variations:
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
nang ma » tang ma, sang ma, nang cao
ve cac » va cac, vien cac

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 ((nang ma) or (lang xa)) hoi. hieu ve cac duc ban hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (lang xa)) hoi. hieu ve cac duc ban hanh vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (lang xa)) hoi. hieu ve cac duc ban hanh vi ((cua tre) or (cuu tre))*.