Perhaps you should try some spelling variations:
cao duoc » tao duoc, co duoc, cao duc
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
hanh vai » hanh vi, hanh va, hanh van
duoc xa » duoc ma, duoc va, duoc ha
cua tre » cua te, cuu tre, cua triet
hieu va » lieu va, hieu qua
nong va » nong van, dong va, cong va
tu nong » tu dong, tu cong, tu tong
va hoi » xa hoi, va hoc, va hoa
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (toc sach)) tu nong va hoi. hieu va cao duoc xa ((hanh vai) OR (hanh tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tu nong va hoi. hieu va cao duoc xa ((hanh vai) OR (hanh tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) tu nong va hoi. hieu va cao duoc xa ((hanh vai) OR (hanh tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) tu nong va hoi. hieu va cao duoc xa ((hanh vai) OR (hanh tai)) cua tre*.