Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
co thuc » do thuc, co thua, mo thuc
tu nang » tru nang, tu nong, tu nano
cuu tre » cua tre, cau tren, cau treo
va cuu » va cau, va chu, va huu
x hoi » xa hoi, o hoi, x ho
va co » vo co

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sach) or (((toc sach) OR (hoc sach)))) tu nang x hoi. hieu va co thuc va hanh va cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (((toc sach) OR (hoc sach)))) tu nang x hoi. hieu va co thuc va hanh va cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (((toc sach) OR (hoc sach)))) tu nang x hoi. hieu va co thuc va hanh va cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (((toc sach) OR (hoc sach)))) tu nang x hoi. hieu va co thuc va hanh va cuu tre*.