Perhaps you should try some spelling variations:
su triet » su tien, ve triet
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
duc van » duc va, duc manh, duc phan
su viet » so viet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
ve cam » ve cham, ve cac, va cam
x hoi » xa hoi, o hoi, x ho

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: tu sach v nang x hoi. hieu ve cam ((duc van) OR (duc tan)) hanh vi ((su triet) OR (su viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach v nang x hoi. hieu ve cam ((duc van) or (duc tan)) hanh vi ((su triet) OR (su viet))~".
• Adding a wildcard symbol may retrieve word variants: tu sach v nang x hoi. hieu ve cam ((duc van) or (duc tan)) hanh vi ((su triet) OR (su viet))*.