Perhaps you should try some spelling variations:
cac truc » cau truc, cac tru, cac trung
hanh tai » thanh tai, hang tai, han tai
hanh vai » hanh vi, hanh va, hanh van
truc va » thuc va, thuc vat, trung va
sach ky » sach y, sach ty, sach kem
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

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

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