Perhaps you should try some spelling variations:
thuat tach » thuat sach, thuat mach, thuat tac
lam truoc » lam thuoc, nam truoc, lam truong
truoc va » truc va, thuoc va, truong va
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
tach ky » thanh ky
vi hoa » voi hoa, bi hoa, vi ha
vi hoc » li hoc, va hoc
va dau » va dao
va lam » van lam, va lap
va hoa » van hoa, va hoc, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat tach ky nang xa hoi. hieu va lam truoc va dau ((((vi hoa) or (vi hoc))) or (va hoa)) viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat tach ky nang xa hoi. hieu va lam truoc va dau ((((vi hoa) OR (vi hoc))) OR (va hoa)) viet.
• Adding a wildcard symbol may retrieve word variants: thuat tach ky nang xa hoi. hieu va lam truoc va dau ((((vi hoa) or (vi hoc))) or (va hoa)) viet*.