Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
va thanh » gia thanh, ban thanh, le thanh
cam thuc » am thuc, nam thuc, cam thu
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
va tinh » may tinh
ty nang » ky nang, ty xang, ty hang
tai cuu » tai cuc, tai buu, tai cua
cuu tre » cua tre, cau tren, cau treo

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 ty nang xa hoi. ((hieu van) OR (hieu va)) cam thuc ((va thanh) OR (va tinh)) tai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ty nang xa hoi. ((hieu van) OR (hieu va)) cam thuc ((va thanh) or (va tinh)) tai cuu tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ty nang xa hoi. ((hieu van) OR (hieu va)) cam thuc ((va thanh) or (va tinh)) tai cuu tre*.