Perhaps you should try some spelling variations:
hieu luan » hieu luat, hieu quan, tieu luan
luan phan » luan van, luan hoan
ve triet » va trien, su triet
van hanh » van thanh, ban hanh, van anh
phan dau » phan tu, hang dau
sach ky » sac ky, sach y, sach kem
dau van » dao van, dam van, dau va
mang xa » lang xa, mang may, dang xay
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
vi ve » va ve, gi ve, ve ve

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) OR (sach ty)) ((mang xa) or (nang ma)) hoi. hieu luan phan dau van hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach ty)) ((mang xa) OR (nang ma)) hoi. hieu luan phan dau van hanh vi ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ky) OR (sach ty)) ((mang xa) or (nang ma)) hoi. hieu luan phan dau van hanh vi ve triet".
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) OR (sach ty)) ((mang xa) or (nang ma)) hoi. hieu luan phan dau van hanh vi ve triet*.