Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
van cac » van hac, van cau, van bac
cua tre » cuu tre, cua triet, dua tren
toc va » hoc va, tuc va, loc va
toc ta » toc tay, toc thai
cua te » cua tu
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: vu sach ky nang x hoi. hieu van cac ((toc va) OR (toc ta)) hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. hieu van cac ((toc va) OR (toc ta)) hanh vi ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. hieu van cac ((toc va) OR (toc ta)) hanh vi ((cua tre) or (cua te))*".