Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
co sach » bo sach, cuon sach, hoc sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
thuc va » thuc vat, thuc dan, thuc day
tinh va » tich va, trinh van, trinh vat
tu sach » thu sach, su sach, te sach
tuc va » truc va, tuc xa, duc va
va cua » va chua, via cua, ca cua
x hoi » xa hoi, o hoi, x ho

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) or (co sach)) ky nang x hoi. hieu ve cham ((tuc va) or (thuc va)) tinh va cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (co sach)) ky nang x hoi. hieu ve cham ((tuc va) OR (thuc va)) tinh va cua viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (co sach)) ky nang x hoi. hieu ve cham ((tuc va) or (thuc va)) tinh va cua viet*.