Perhaps you should try some spelling variations:
su triet » su tien, ve triet
tu sach » thu sach, su sach, te sach
dua ban » dia ban, cua ban, qua ban
duc ban » duc tan, duc van, duc man
su viet » so viet
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
sach v » sach va, sach y, sach 2
nang o » nang co, nang ho, nang ro
v nang » va nang, vu nang, van nang
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 v nang o hoi. hieu ve cac ((duc ban) or (dua ban)) hanh vi ((su triet) OR (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach v nang o hoi. hieu ve cac ((duc ban) OR (dua ban)) hanh vi ((su triet) OR (su viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang o hoi. hieu ve cac ((duc ban) or (dua ban)) hanh vi ((su triet) OR (su viet))*".