Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
vu nang » vuc nang, va nang, vu dang
hieu ve » hieu va, hieu van
duc ban » duc tan, duc van, dua ban
qua ban » cua ban, qua quan
hanh ki » hanh vi, hanh ky, hanh kien
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho
ki su » ky su

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 vu nang x hoi. hieu ve cac ((duc ban) or (qua ban)) hanh ki su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu nang x hoi. hieu ve cac ((duc ban) OR (qua ban)) hanh ki su triet*.