Perhaps you should try some spelling variations:
thien van » thi van
ve triet » va trien
su triet » su viet, su tien
ban hanh » ban hang
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
te sach » toc sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
xang ma » tang ma, nang ma, sang ma
ma hoi » mai hoi, xa hoi, ma hoa

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

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