Perhaps you should try some spelling variations:
luan phan » luan van, luan hoan
hieu luan » hieu luat, hieu quan, tieu luan
thu sach » tu sach, thuat sach, thuoc sach
phan duc » pham duc, phan tu, phan dau
ve triet » va trien, su triet
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
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: thu sach ky ((mang may) or (nang cao)) hoi. hieu luan phan duc va hanh vi ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky ((mang may) OR (nang cao)) hoi. hieu luan phan duc va hanh vi ve triet.
• Adding a wildcard symbol may retrieve word variants: thu sach ky ((mang may) or (nang cao)) hoi. hieu luan phan duc va hanh vi ve triet*.