Perhaps you should try some spelling variations:
dinh viet » ninh viet, danh viet, trinh viet
luu tre » luu tru, cuu tre, luy tre
dinh vi » dinh ve, dinh tri, dinh thi
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
ve cham » va cham, ve chat, ve chim
vu cham » va cham, vu kham, tu cham
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky dang xa hoi. hieu ((ve cham) or (vu cham)) hoc va ((dinh vi) OR (dinh viet)) luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky dang xa hoi. hieu ((ve cham) OR (vu cham)) hoc va ((dinh vi) OR (dinh viet)) luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky dang xa hoi. hieu ((ve cham) or (vu cham)) hoc va ((dinh vi) OR (dinh viet)) luu tre".
• Adding a wildcard symbol may retrieve word variants: tu sac ky dang xa hoi. hieu ((ve cham) or (vu cham)) hoc va ((dinh vi) OR (dinh viet)) luu tre*.