Best Balsa Wood Bridge How Do You Make A Really Strong Balsa Wood Bridge?

How do you make a really strong balsa wood bridge? - best balsa wood bridge

ok so I have a bridge made of balsa wood ..
What are good design and a solid structure?
I need some details, and perhaps links.
I know that the triangles are the strongest, but what can I do to ensure you have a good amount of mass before the break? Thank you.