Perhaps you should try some spelling variations:
lam truoc » nam truoc, lam truong, nam thuoc
lam thuoc » nam thuoc, am thuc, cay thuoc
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
sac ky » sai ky
vi hoa » voi hoa, vi hoc, va hoa
x hoi » xa hoi, o hoi, x ho

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 x hoi. hieu van ((lam truoc) OR (lam thuoc)) van hanh vi hoa viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat ((sac ky) OR (cac ky)) nang x hoi. hieu van ((lam truoc) OR (lam thuoc)) van hanh vi hoa viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat ((sac ky) or (cac ky)) nang x hoi. hieu van ((lam truoc) OR (lam thuoc)) van hanh vi hoa viet".
• Adding a wildcard symbol may retrieve word variants: thuat ((sac ky) or (cac ky)) nang x hoi. hieu van ((lam truoc) OR (lam thuoc)) van hanh vi hoa viet*.