Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
doi cua » dai cua, hoi cua
sach ky » sac ky, sach y, sach ty
te sach » toc sach
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
van cau » van dau, van hau, van chat
cau so » cau do, cau o, cao so
so van » su van, vo van
di cua » dai cua, de cua, do cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang xa) or (lang xa)) hoi. hieu van cau so van hanh ((di cua) OR (doi cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (lang xa)) hoi. hieu van cau so van hanh ((di cua) OR (doi cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang xa) or (lang xa)) hoi. hieu van cau so van hanh ((di cua) OR (doi cua)) triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (lang xa)) hoi. hieu van cau so van hanh ((di cua) OR (doi cua)) triet*.