Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
chat luc » chat xuc, chat lua, nhan luc
doanh va » doan va, doanh tai, doanh cua
va doanh » van doanh, vay doanh, va danh
cua viet » ca viet, hoa viet, cua vat
ky danh » ky anh
hieu ve » hieu va, hieu van
ve chat » va chat, van chat
ky dang » ky nang
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((ky lang) OR (((ky dang) OR (ky danh)))) xa hoi. hieu ve chat luc va doanh va cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ky lang) or (((ky dang) OR (ky danh)))) xa hoi. hieu ve chat luc va doanh va cua viet~".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ky lang) or (((ky dang) OR (ky danh)))) xa hoi. hieu ve chat luc va doanh va cua viet*.