Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
dau luan » dan luan, dat luan, khau luan
luan ban » luan van, luan san, luan han
su sach » so sach, vu sach
nang xa » nang x, nang ma, mang xa
doi cua » dai cua, hoi cua
moi cua » hoi cua, moi quan, cuoi cua
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
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 xa) or (lang xa)) hoi. hieu va dau luan ban thanh ((moi cua) OR (doi cua)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (lang xa)) hoi. hieu va dau luan ban thanh ((moi cua) OR (doi cua)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) or (lang xa)) hoi. hieu va dau luan ban thanh ((moi cua) OR (doi cua)) te".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (lang xa)) hoi. hieu va dau luan ban thanh ((moi cua) OR (doi cua)) te*.