Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vien cac » vien bach, vien dai, vien da
va trinh » van trinh, lap trinh, qua trinh
cac duc » cac du, cao duc, cac dac
doc cua » hoc cua, doi cua, do cua
va tinh » may tinh
su sach » so sach, vu sach
kv nang » ky nang, ki nang, ke nang
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang

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 ((v nang) or (kv nang)) xa hoi. hieu vien cac duc ((va trinh) OR (va tinh)) doc cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (kv nang)) xa hoi. hieu vien cac duc ((va trinh) OR (va tinh)) doc cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) or (kv nang)) xa hoi. hieu vien cac duc ((va trinh) OR (va tinh)) doc cua tre*".