Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hiem he » hiem xe, thien he, hiem cho
lai cua » dai cua, hai cua, lai chau
dan lai » dan loai, dan lap, dan lat
nam dan » nam dinh
thu nam » tu nam, thu nhap, thu nhat
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
hieu he » hieu ve, hieu le, hieu hien
mai hoi » mai khoi, dai hoi, lai hoi
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 mai hoi. ((hieu he) OR (hiem he)) nam thu nam dan lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sac ky)) nang mai hoi. ((hieu he) OR (hiem he)) nam thu nam dan lai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) or (sac ky)) nang mai hoi. ((hieu he) OR (hiem he)) nam thu nam dan lai cua tre*".