Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
cac luc » cau luc, coc luc, cac nuoc
cuc tre » duc tre, cua tre, cuc thue
luc van » luoc van, luu van, duc van
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
co hoa » co hoat, cho hoa, co hoc
o hoa » do hoa, so hoa, o ha

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((o hoa) OR (co hoa)). thieu nien cac luc van hanh tai ((cuc tre) OR (cuu tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((o hoa) or (co hoa)). thieu nien cac luc van hanh tai ((cuc tre) OR (cuu tre))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((o hoa) or (co hoa)). thieu nien cac luc van hanh tai ((cuc tre) OR (cuu tre))*.