Perhaps you should try some spelling variations:
xac danh » xac dinh, tac danh, sach danh
danh sai » dung sai, danh bat, danh dau
tu sach » thu sach, su sach, te sach
hieu he » hieu ve, hiem he, hieu le
thu xac » thau xay
cuu tre » cua tre, cau tren, cau treo
y tang » ky tang, 6 tang, 5 tang
7 tang » 6 tang
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 ((y tang) OR (7 tang)) ma hoa. hieu he nam thu xac danh sai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y tang) OR (7 tang)) ma hoa. hieu he nam thu xac danh sai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y tang) OR (7 tang)) ma hoa. hieu he nam thu xac danh sai cuu tre*.