Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
sach thu » sach thue, sach thieu, sach tham
thu nang » thi nang, thu hang, thu bang
van hanh » van thanh, ban hanh, van anh
xuc van » duc van, luc van, vuc van
ve cham » va cham, ve chat, vu cham
su sach » so sach, vu sach
vi cua » vai cua, di cua
ve cam » ve cac, va cam, ve cai
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu nang ((x hoi) OR (o hoi)). hieu ((ve cam) or (ve cham)) xuc van hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu nang ((x hoi) OR (o hoi)). hieu ((ve cam) OR (ve cham)) xuc van hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu nang ((x hoi) OR (o hoi)). hieu ((ve cam) or (ve cham)) xuc van hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: su sach thu nang ((x hoi) OR (o hoi)). hieu ((ve cam) or (ve cham)) xuc van hanh vi cua viet*.