Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
doanh van » doan van, doanh va, doanh ban
vien cam » vien cac, vien cao, vien nam
mai khoi » mai khoa, tai khoa, cac khoi
van cua » vang cua, ban cua, dan cua
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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 ky tang ((ma hoi) or (mai khoi)). hieu vien cam ((xuc vay) OR (xuc hay)) doanh van cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ((ma hoi) OR (mai khoi)). hieu vien cam ((xuc vay) OR (xuc hay)) doanh van cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky tang ((ma hoi) or (mai khoi)). hieu vien cam ((xuc vay) OR (xuc hay)) doanh van cua te*".