Perhaps you should try some spelling variations:
thien van » thi van
su triet » su viet, su tien, ve triet
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
hanh ki » hanh vi, hanh ky, hanh kien
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va, hieu van
xang ma » tang ma, nang ma, sang ma
ma hoi » mai hoi, xa hoi, ma hoa
ki su » ky su

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) OR (toc sach)) ty xang ma hoi. ((hieu ve) OR (thien van)) cam duc ban hanh ki su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty xang ma hoi. ((hieu ve) or (thien van)) cam duc ban hanh ki su triet~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty xang ma hoi. ((hieu ve) or (thien van)) cam duc ban hanh ki su triet*.