Perhaps you should try some spelling variations:
nhanh hai » nhanh thai, thanh hai, nhanh ha
lan nhanh » luan thanh, nhan nhanh, lang thanh
cam quoc » cao quoc, nam quoc, han quoc
cac quoc » cac nuoc, cac cuoc, cao quoc
hieu van » hieu va, thien van, lieu va
hai cua » thai cua, dai cua, hoi cua
sach ky » sach y, sach ty, sach kem
lang xa » lang ha, dang xay, lang van
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)) lang xa hoi. hieu van ((cam quoc) OR (cac 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 ((cam quoc) OR (cac 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 ((cam quoc) OR (cac quoc)) lan nhanh hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sac ky)) lang xa hoi. hieu van ((cam quoc) OR (cac quoc)) lan nhanh hai cua tre*.