Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
nam thuc » nam thuoc, am thuc, nam thu
vat dan » va dan, van dan, vat ran
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
va nam » van nam, ha nam, va nay
dan va » doan va, dan ca, ban va
va cuu » va cau, va chu, va huu
ha hoi » hoa hoi, ha noi, xa hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ((ky lang) OR (ky tang)) ha hoi. hieu va nam thuc vat dan va cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ((ky lang) OR (ky tang)) ha hoi. hieu va nam thuc vat dan va cuu tre~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ((ky lang) OR (ky tang)) ha hoi. hieu va nam thuc vat dan va cuu tre*.