Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tinh vai » tinh va, tinh hai, tinh bai
vai cua » dai cua, hai cua, lai cua
va tinh » may tinh
cac tac » cac toc, cac bac, cac dac
van cac » van hac, van cau, van bac
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
ky tang » ky nang, kho tang, ky trong
ma hoi » mai hoi, xa hoi, ma hoa
tac va » tac da, tac xa, tuc va
su sac » su sach, su cac, su xac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sac) or (cu cao)) ((ky tang) OR (ky dang)) ma hoi. hieu van cac tac va tinh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (cu cao)) ((ky tang) OR (ky dang)) ma hoi. hieu van cac tac va tinh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) or (cu cao)) ((ky tang) OR (ky dang)) ma hoi. hieu van cac tac va tinh vai cua tre*".