Perhaps you should try some spelling variations:
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
va lanh » va lang, va danh, va hanh
dao cua » dai cua, day cua, dan cua
cua tre » cua te, cuu tre, cua triet
vu san » va san, vu ban
san ky » sang ky, van ky, dan ky
va cam » va cham, va cac, va cai
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu san ky ((nang xa) OR (lang xa)) hoi. lieu ((va cam) or (va cao)) duc va lanh dao cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu san ky ((nang xa) OR (lang xa)) hoi. lieu ((va cam) OR (va cao)) duc va lanh dao cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu san ky ((nang xa) OR (lang xa)) hoi. lieu ((va cam) or (va cao)) duc va lanh dao cua tre".
• Adding a wildcard symbol may retrieve word variants: vu san ky ((nang xa) OR (lang xa)) hoi. lieu ((va cam) or (va cao)) duc va lanh dao cua tre*.