Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hieu van » thien van, lieu va, hieu ve
chat luc » chat xuc, chat lua, nhan luc
sach ty » sach y, sach tu, xach tay
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
han tri » han tai, van tri, thanh tri
luc va » duc va, tuc va, loc va
va han » va phan, van han, va hanh
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 ((sach ty) OR (sach thu)) nang xa hoi. ((hieu van) or (hieu va)) chat luc va han tri va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ty) OR (sach thu)) nang xa hoi. ((hieu van) OR (hieu va)) chat luc va han tri va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ty) OR (sach thu)) nang xa hoi. ((hieu van) or (hieu va)) chat luc va han tri va thiet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ty) OR (sach thu)) nang xa hoi. ((hieu van) or (hieu va)) chat luc va han tri va thiet*.