Perhaps you should try some spelling variations:
thieu nien » thien nhien
thu sach » thuat sach, thuoc sach, thu hoach
nien coc » nien cong, vien cac, dien cuc
van hanh » van thanh, ban hanh, van anh
hanh tai » thanh tai, hang tai, han tai
tu sach » su sach, te sach, tu cach
luc van » luoc van, luu van, duc van
cuc tre » duc tre, cua tre, cuu tre
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) OR (thu sach)) ky nang ((o hoa) OR (co hoa)). thieu nien coc luc van hanh tai cuc tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang ((o hoa) or (co hoa)). thieu nien coc luc van hanh tai cuc tre~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang ((o hoa) or (co hoa)). thieu nien coc luc van hanh tai cuc tre*.