Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
toc sach » hoc sach, doc sach, thuoc sach
sach ky » sac ky, sach y, sach ty
dan tai » van tai, dan thi, han tai
dan vai » dan va, dan vat, den vai
thuc ca » thuc cua, thuc can, thuc cao
cuu tre » cua tre, cau tren, cau treo
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
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: toc sach ky ((nang xa) OR (nang ma)) hoi. hieu va nam thuc ca ((dan vai) or (dan tai)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang xa) OR (nang ma)) hoi. hieu va nam thuc ca ((dan vai) OR (dan tai)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((nang xa) OR (nang ma)) hoi. hieu va nam thuc ca ((dan vai) or (dan tai)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang xa) OR (nang ma)) hoi. hieu va nam thuc ca ((dan vai) or (dan tai)) cuu tre*.