Perhaps you should try some spelling variations:
chat soc » cham soc, chat hoc, chat doc
van chat » cao chat
hieu van » hieu va, thien van, lieu va
ky danh » ky anh
ky dang » ky nang
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
tu sach » thu sach, su sach, te sach
ha hoi » hoa hoi, ha noi, xa hoi

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 ((ky dang) OR (ky danh)) ha hoi. hieu van chat soc ((va danh) or (va hanh)) dai cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky danh)) ha hoi. hieu van chat soc ((va danh) OR (va hanh)) dai cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) OR (ky danh)) ha hoi. hieu van chat soc ((va danh) or (va hanh)) dai cua vat".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) OR (ky danh)) ha hoi. hieu van chat soc ((va danh) or (va hanh)) dai cua vat*.