Perhaps you should try some spelling variations:
thuat tac » thuat tach, thuat tao, thuat tai
dua tren » dung tren
nang xa » lang xa, nang ma, mang xa
dan tai » van tai, dan thi, han tai
tac ky » tac ke, cac ky, tap ky
va cao » va cac, va co, va dao
va dan » ca dan, va dao, va dau
cua te » cua tu
su va » su van, tu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat tac ky ((nang xa) or (nang x)) hoi. lieu va cao su va dan tai ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat tac ky ((nang xa) OR (nang x)) hoi. lieu va cao su va dan tai ((dua tren) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: thuat tac ky ((nang xa) or (nang x)) hoi. lieu va cao su va dan tai ((dua tren) or (cua te))*.