Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
su triet » su viet, su tien, ve triet
vien cac » vien bach, vien dai, vien da
su sach » so sach, vu sach
duc ban » duc tan, duc van, dua ban
qua ban » cua ban, qua quan
hanh ki » hanh vi, hanh ky, hanh kien
tu sach » thu sach, te sach, tu cach
v nang » va nang, vu nang, van nang
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) OR (su sach)) v nang x hoi. hieu vien 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) OR (su sach)) v nang x hoi. hieu vien cac ((duc ban) OR (qua ban)) hanh ki su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) v nang x hoi. hieu vien cac ((duc ban) or (qua ban)) hanh ki su triet*".