Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
lan nhanh » luan thanh, nhan nhanh, lang thanh
quoc lan » quoc ban, nuoc luan, quoc quan
cam quoc » cac quoc, cao quoc, nam quoc
hieu van » thien van, lieu va, hieu ve
hieu va » lieu va, hieu qua
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
lang xa » lang ha, dang xay, lang van
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)) lang xa hoi. ((hieu van) OR (hieu va)) cam quoc lan nhanh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) lang xa hoi. ((hieu van) OR (hieu va)) cam quoc lan nhanh hai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) lang xa hoi. ((hieu van) OR (hieu va)) cam quoc lan nhanh hai cua tre*".