Perhaps you should try some spelling variations:
nang xa » lang xa, nang ma, mang xa
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
duc van » duc va, duc manh, duc phan
han tai » hang tai, nhan tai, van tai
vu sac » vu sach, vu san, va sac
sac ky » cac ky, sai ky
tai va » thai va, mai va, tri va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sac ky ((nang xa) or (nang x)) hoi. hieu vu cham ((duc van) OR (duc tan)) han tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sac ky ((nang xa) OR (nang x)) hoi. hieu vu cham ((duc van) OR (duc tan)) han tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sac ky ((nang xa) or (nang x)) hoi. hieu vu cham ((duc van) OR (duc tan)) han tai va thiet".
• Adding a wildcard symbol may retrieve word variants: vu sac ky ((nang xa) or (nang x)) hoi. hieu vu cham ((duc van) OR (duc tan)) han tai va thiet*.