Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van tham » van thanh, van tuan, van chat
van cham » van chat, va cham, van pham
cua viet » ca viet, hoa viet, cua vat
nang xa » nang x, lang xa, nang ma
ly nang » ky nang, ly hang, ly vang
vu sach » vu bach, su sach, vu khach
va hanh » van hanh, va thanh, va danh
soc va » hoc va, loc va, doc va
vi cua » vai cua, di 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: ((toc sach) OR (vu sach)) ly nang xa hoi. hieu ((van cham) OR (van tham)) soc va hanh vi cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (vu sach)) ly nang xa hoi. hieu ((van cham) OR (van tham)) soc va hanh vi cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (vu sach)) ly nang xa hoi. hieu ((van cham) OR (van tham)) soc va hanh vi cua viet*.