Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
tinh vai » tinh va, tinh hai, tinh bai
van cham » van chat, van tham, va cham
hieu van » hieu va, thien van, lieu va
hoc sach » hoc sinh, hoc cac, hoc anh
thuc va » thuc vat, thuc dan, thuc day
vai cua » dai cua, hai cua, lai cua
tu sach » thu sach, su sach, te sach
tuc va » truc va, tuc xa, duc va
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 (hoc sach)) ky nang x hoi. hieu van cham ((tuc va) OR (thuc va)) tinh vai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky nang x hoi. hieu van cham ((tuc va) OR (thuc va)) tinh vai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (hoc sach)) ky nang x hoi. hieu van cham ((tuc va) OR (thuc va)) tinh vai cua viet*".