Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
van chat » cao chat
chat luc » chat xuc, chat lua, nhan luc
chua tre » chua tri, chua trieu, cho tre
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
va doan » va doanh, van doan, va dan
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va

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

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