Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
va trien » va truyen, va thiet, va tuyen
van hanh » van thanh, ban hanh, van anh
vien cac » vien bach, vien dai, vien da
toc van » hoc van, toc san, tac van
cac toc » cac toi, cac nuoc, cac thoi
vu sach » vu bach, su sach, vu khach
nang xa » nang x, nang ma, mang xa
so sach » so sanh, bo sach, co sach
lang xa » lang ha, dang xay, lang van
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (so sach)) ky ((nang xa) OR (lang xa)) hoi. hieu vien cac toc van hanh vi va trien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sach)) ky ((nang xa) OR (lang xa)) hoi. hieu vien cac toc van hanh vi va trien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (so sach)) ky ((nang xa) OR (lang xa)) hoi. hieu vien cac toc van hanh vi va trien".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sach)) ky ((nang xa) OR (lang xa)) hoi. hieu vien cac toc van hanh vi va trien*.