Perhaps you should try some spelling variations:
thuc day » thuc dan
sach ky » sach y, sach ty, sach kem
tai cuu » tai cuc, tai buu, tai cua
dan tai » van tai, dan thi, han tai
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
va hoe » van hoe, va hoc, va hoa
sac ky » cac ky, sai ky
va nam » van nam, ha nam, va nay

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((sach ky) OR (sac ky)) hang va hoe. hieu va nam ((thuc vat) or (thuc day)) dan tai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((sach ky) OR (sac ky)) hang va hoe. hieu va nam ((thuc vat) OR (thuc day)) dan tai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((sach ky) OR (sac ky)) hang va hoe. hieu va nam ((thuc vat) or (thuc day)) dan tai cuu tre".
• Adding a wildcard symbol may retrieve word variants: doc ((sach ky) OR (sac ky)) hang va hoe. hieu va nam ((thuc vat) or (thuc day)) dan tai cuu tre*.