Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
ban hanh » ban hang
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
hieu ve » hieu va, hieu van
tu sach » thu sach, su sach, tu cach
te sach » toc sach
v nang » va nang, vu nang, van nang
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, x ho, 5 hoi
vi su » va su, ve su, ki su
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (te sach)) v nang ((x hoi) or (o hoi)). hieu ve cam duc ban hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) v nang ((x hoi) OR (o hoi)). hieu ve cam duc ban hanh vi su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) v nang ((x hoi) or (o hoi)). hieu ve cam duc ban hanh vi su triet*".