Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
trinh di » trinh do, trinh dien, trinh dinh
va trinh » van trinh, va tinh, lap trinh
nang mai » nang ma, nang tai, lang mai
tu sach » thu sach, te sach, tu cach
cua tre » cua te, cua triet, dua tren
vien da » vien dai, hien dai
mai hoi » mai khoi, dai hoi, lai hoi
su sach » so sach, vu sach
cuu tre » cau tren, cau treo
da tuc » dao tuc, va tuc, da tac
tuc va » thuc va, truc va, tuc xa

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 nang mai hoi. hieu vien da tuc va trinh di ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang mai hoi. hieu vien da tuc va trinh di ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky nang mai hoi. hieu vien da tuc va trinh di ((cua tre) OR (cuu tre))*".