Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van nhanh » van hanh, van khanh, van nhan
nang tai » hang tai, tang tai, sang tai
nang dau » hang dau, xang dau, nang du
cua tre » cua te, cuu tre, cua triet
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
cac luc » cau luc, coc luc, cac nuoc
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky ((nang tai) or (nang dau)) hoi. hieu ve cac luc ((van nhanh) OR (van thanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky ((nang tai) OR (nang dau)) hoi. hieu ve cac luc ((van nhanh) OR (van thanh)) hai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky ((nang tai) or (nang dau)) hoi. hieu ve cac luc ((van nhanh) OR (van thanh)) hai cua tre*".