Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dien cuc » dien tu, dieu cua, vien cac
chat soc » cham soc, chat hoc, chat doc
van nang » van quang, van ban, van dong
hieu va » lieu va, hieu qua
va chat » van chat, va phat, cao chat
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
v nang » va nang, vu nang, voi nang
cuc te » cua te, cuc thue, cuc tieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((v nang) or (van nang)) xa hoi. hieu va chat soc ((va hanh) OR (va danh)) dien cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((v nang) OR (van nang)) xa hoi. hieu va chat soc ((va hanh) OR (va danh)) dien cuc te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((v nang) or (van nang)) xa hoi. hieu va chat soc ((va hanh) OR (va danh)) dien cuc te".
• Adding a wildcard symbol may retrieve word variants: toc sach ((v nang) or (van nang)) xa hoi. hieu va chat soc ((va hanh) OR (va danh)) dien cuc te*.