Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
van thanh » ban thanh, van tuan
thanh lai » thanh hai, thanh lap, thanh loi
vien cac » vien bach, vien dai, vien da
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
cac duc » cac du, cao duc, cac dac
duc van » duc va, duc tan, duc manh
y nang » ky nang, ly nang, v nang

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 y nang ((mai hoi) or (xa hoi)). hieu vien cac duc van thanh lai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((mai hoi) OR (xa hoi)). hieu vien cac duc van thanh lai su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((mai hoi) or (xa hoi)). hieu vien cac duc van thanh lai su triet*.