Perhaps you should try some spelling variations:
nhieu vien » nhieu viec, nhiet dien, thieu nien
kho tang » cao tang
trinh ve » trinh he, trinh va, trinh vi
va trinh » van trinh, va tinh, lap trinh
vien cac » vien bach, vien dai, vien da
tu sach » thu sach, te sach, tu cach
cac duc » cac du, cao duc, cac dac
ky tang » ky nang, ky dang, ky trong
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, ma hoa
ve cua » le cua, de cua, te cua

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)) ((ky tang) OR (kho tang)) ma hoi. nhieu vien cac duc va trinh ve cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ((ky tang) OR (kho tang)) ma hoi. nhieu vien cac duc va trinh ve cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ((ky tang) OR (kho tang)) ma hoi. nhieu vien cac duc va trinh ve cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ((ky tang) OR (kho tang)) ma hoi. nhieu vien cac duc va trinh ve cua tre*.