Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
doanh va » doan va, doanh tai, doanh cua
va doanh » van doanh, vay doanh, va danh
chat luc » chat xuc, chat lua, nhan luc
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
luc va » duc va, tuc va, loc va
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((ky lang) or (ky dang)) xa hoi. ((hieu ve) OR (hieu van)) chat luc va doanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((ky lang) OR (ky dang)) xa hoi. ((hieu ve) OR (hieu van)) chat luc va doanh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ky lang) or (ky dang)) xa hoi. ((hieu ve) OR (hieu van)) chat luc va doanh va cua tre*".