Perhaps you should try some spelling variations:
sach kem » hanh kem
xac danh » xac dinh, tac danh, sach danh
nang ma » tang ma, sang ma, nang cao
hieu he » hieu ve, hiem he, hieu le
thu xac » thau xay
sai cua » dai cua, lai cua, bai cua
hai cua » thai cua, dai cua, hoi cua
he nam » ha nam, nghe nam

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 kem) or (sach y)) nang ma hoa. hieu he nam thu xac danh ((sai cua) OR (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach kem) OR (sach y)) nang ma hoa. hieu he nam thu xac danh ((sai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach kem) or (sach y)) nang ma hoa. hieu he nam thu xac danh ((sai cua) OR (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach kem) or (sach y)) nang ma hoa. hieu he nam thu xac danh ((sai cua) OR (hai cua)) tre*.