Perhaps you should try some spelling variations:
dap truoc » phap truoc, lam truoc, nam truoc
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
sac ky » sai ky
va dap » va dau
va dan » ca dan, va dau, va dai
va dao » ca dao
di hoa » dai hoa, doi hoa, do 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 ((sac ky) or (cac ky)) nang xa hoi. hieu va dap truoc ((va dan) OR (va dao)) di hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sac ky) OR (cac ky)) nang xa hoi. hieu va dap truoc ((va dan) OR (va dao)) di hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sac ky) or (cac ky)) nang xa hoi. hieu va dap truoc ((va dan) OR (va dao)) di hoa viet".
• Adding a wildcard symbol may retrieve word variants: thuat ((sac ky) or (cac ky)) nang xa hoi. hieu va dap truoc ((va dan) OR (va dao)) di hoa viet*.