Perhaps you should try some spelling variations:
ban hanh » ban hang
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
dau tuc » dau tu, dao tuc, cau truc
tuc ban » thuc ban, truc ban, tu ban
hanh di » hanh vi, hanh de, hang di
cuu tre » cua tre, cau treo
ma hoi » mai hoi, xa hoi, ma hoa
va dau » va dao

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 ky nang ma hoi. lieu va dau tuc ban hanh di ((cuu tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ma hoi. lieu va dau tuc ban hanh di ((cuu tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ma hoi. lieu va dau tuc ban hanh di ((cuu tre) or (cau tren))*.