Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
vu sach » vu bach, su sach, vu khach
duoc va » nuoc va, duc va, duoc ma
sach ky » sac ky, sach y, sach ty
tuoc va » thuoc va, nuoc va, tuc va
nang xa » nang x, lang xa, nang ma
tu cuu » tu huu, tu cua, tu chu

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 ky nang xa hoi. hieu vien bach ((tuoc va) or (duoc va)) danh ((du cuu) OR (tu cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang xa hoi. hieu vien bach ((tuoc va) OR (duoc va)) danh ((du cuu) OR (tu cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang xa hoi. hieu vien bach ((tuoc va) or (duoc va)) danh ((du cuu) OR (tu cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang xa hoi. hieu vien bach ((tuoc va) or (duoc va)) danh ((du cuu) OR (tu cuu)) tre*.