Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
va doanh » van doanh, vay doanh, va danh
chat luc » chat xuc, chat lua, nhan luc
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
cua cua » cua chua, qua cua, cua cha
ve chat » va chat, van chat
luc va » duc va, tuc va, loc va
ca cua » co cua

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

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