Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
hieu van » hieu va, thien van, lieu va
dan tai » van tai, dan thi, han tai
dan vai » dan va, dan vat, den vai
cuu tre » cua tre, cau tren, cau treo
sach ky » sac ky, sach ty, sach kem
lang xa » lang ha, dang xay, lang van
van am » van nam, van lam, van dam

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((sach ky) or (sach y)) lang xa hoi. hieu van am thuc day ((dan vai) OR (dan tai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach ky) OR (sach y)) lang xa hoi. hieu van am thuc day ((dan vai) OR (dan tai)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach ky) or (sach y)) lang xa hoi. hieu van am thuc day ((dan vai) OR (dan tai)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach ky) or (sach y)) lang xa hoi. hieu van am thuc day ((dan vai) OR (dan tai)) cuu tre*.