Perhaps you should try some spelling variations:
thanh cho » thanh pho, thanh cha, thanh chu
dan tren » dat tren, dau tren, van tren
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
can tre » ban tre, van tren, gian tre
tu sach » thu sach, su sach, te sach
may hoi » may thoi, tay hoi, mai hoi
ky mang » ky nang, ke mang, ky dang
hieu va » lieu va, hieu qua

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: ((tu sach) OR (toc sach)) ky mang may hoi. hieu va cac nuoc va thanh cho ((can tre) OR (dan tren))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky mang may hoi. hieu va cac nuoc va thanh cho ((can tre) OR (dan tren))~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky mang may hoi. hieu va cac nuoc va thanh cho ((can tre) OR (dan tren))*.