Perhaps you should try some spelling variations:
cac viet » cach viet, bac viet, ca viet
hanh va » hang va, hanh vi
sach ky » sac ky, sach y, sach ty
te sach » toc sach
nang xa » lang xa, nang ma, mang xa
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
xac va » tac va, ac va, bac va
luc va » duc va, tuc va, loc va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang xa) or (nang x)) hoi. hieu vu cham ((xac va) or (luc va)) hanh va cac viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang xa) OR (nang x)) hoi. hieu vu cham ((xac va) OR (luc va)) hanh va cac viet.
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang xa) or (nang x)) hoi. hieu vu cham ((xac va) or (luc va)) hanh va cac viet*.