Perhaps you should try some spelling variations:
xach tay » canh tay
hieu van » hieu va, thien van, lieu va
van cham » van chat, van tham, va cham
thai va » thai van
soc va » hoc va, loc va, doc va
va han » va phan, van han, va hanh
tai va » mai va, tri va, dai 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: tu ((xach tay) or (sach y)) nang x hoi. hieu van cham soc va han ((tai va) OR (thai va)) thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((xach tay) OR (sach y)) nang x hoi. hieu van cham soc va han ((tai va) OR (thai va)) thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((xach tay) or (sach y)) nang x hoi. hieu van cham soc va han ((tai va) OR (thai va)) thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((xach tay) or (sach y)) nang x hoi. hieu van cham soc va han ((tai va) OR (thai va)) thiet*.