Perhaps you should try some spelling variations:
hieu luan » hieu luat, hieu quan, tieu luan
luan phan » luan van, luan hoan
su triet » su viet, su tien
phan duc » pham duc, phan tu, phan dau
thu sach » tu sach, thuat sach, thuoc sach
ve triet » va trien
sach ky » sac ky, sach y, sach ty
mang xa » lang xa, mang may, dang xay
va hanh » van hanh, va thanh, va danh

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky ((mang xa) or (nang cao)) hoi. hieu luan phan duc va hanh vi ((su triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((mang xa) OR (nang cao)) hoi. hieu luan phan duc va hanh vi ((su triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky ((mang xa) or (nang cao)) hoi. hieu luan phan duc va hanh vi ((su triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((mang xa) or (nang cao)) hoi. hieu luan phan duc va hanh vi ((su triet) OR (ve triet))*.