Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
cua triet » cua viet, su triet, va triet
vien cac » vien bach, vien dai, vien da
van dinh » van minh, van dich, va dinh
dinh vai » dinh van, dinh vi, dinh va
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, dua tren
ma hoi » mai hoi, xa hoi, ma hoa
cac lo » cac lop, cac co, cac bo
lo van » le van, vo van, so van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang ma hoi. hieu vien cac lo van dinh vai ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ma hoi. hieu vien cac lo van dinh vai ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ma hoi. hieu vien cac lo van dinh vai ((cua tre) or (cua triet))*.