Perhaps you should try some spelling variations:
phan tai » pham tai, nhan tai, phan thi
vu cham » va cham, vu kham, tu cham
va chat » van chat, va phat, cao chat
va phan » van phan, va phat, va phap
xuc va » duc va, tuc va, luc va
sac ky » cac ky
tai va » thai va, mai va, tri va
x hoi » xa hoi, o hoi, x ho
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sac ky) OR (sai ky)) nang x hoi. hieu ((vu cham) or (va chat)) xuc va phan tai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sac ky) OR (sai ky)) nang x hoi. hieu ((vu cham) OR (va chat)) xuc va phan tai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sac ky) OR (sai ky)) nang x hoi. hieu ((vu cham) or (va chat)) xuc va phan tai va thiet".
• Adding a wildcard symbol may retrieve word variants: su ((sac ky) OR (sai ky)) nang x hoi. hieu ((vu cham) or (va chat)) xuc va phan tai va thiet*.