Perhaps you should try some spelling variations:
nhanh thai » nhanh thi, nhanh thanh, nhanh thang
thanh thai » thanh hai, thanh tai, thanh thao
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
cau duc » cao duc, cau luc, chu duc
duc ban » duc tan, duc van, dua ban
van cau » van dau, van hau, van chat
nang xa » nang x, lang xa, nang ma
sai ky » sac 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 ((sai ky) or (cac ky)) nang xa hoi. hieu van cau duc ban ((thanh thai) OR (nhanh thai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sai ky) OR (cac ky)) nang xa hoi. hieu van cau duc ban ((thanh thai) OR (nhanh thai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sai ky) or (cac ky)) nang xa hoi. hieu van cau duc ban ((thanh thai) OR (nhanh thai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sai ky) or (cac ky)) nang xa hoi. hieu van cau duc ban ((thanh thai) OR (nhanh thai)) cua tre*.