Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
han tai » hang tai, nhan tai, van tai
y nang » ky nang, ly nang, v nang
soc va » hoc va, loc va, doc va
va han » va phan, van han, va hanh
tai va » thai va, mai va, tri va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang xa hoi. ((hieu van) OR (hieu va)) cham soc va han tai va (thiet or thieu)~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. ((hieu van) OR (hieu va)) cham soc va han tai va (thiet OR thieu).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. ((hieu van) OR (hieu va)) cham soc va han tai va (thiet or thieu)".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. ((hieu van) OR (hieu va)) cham soc va han tai va (thiet or thieu)*.