Time of concentration - Difference between large and small basins I am looking for any academic reference (i.e. articles) regarding the time of concentration for large and small basins.

E.g. I would expect that a large basin (area > 1,500 km^2) will flood (or reach its max peak flow) later in time (e.g. 1-2 days later) when compared to a small basin if the same amount of rain will fall in both of them.
This is a difficult question since time of concentration ($t_c$) can in theory,  vary substantially, for two basins of equal size.

Off the top of my head, I can imagine several other variables that would be necessary to determine $t_c$: drainage density, basin relief, basin length, surface roughness (Mannings coefficient), and rainfall statistics. There's certainly others too. 

I found a paper titled The characteristic time scale for basin hydrological response using radar data is freely available. There is a discussion of $t_c$ beginning on page 93 at bullet point number 2. They cite other papers in their discussion that would be worth tracking down and reading. 

Note they present an empirical equation for $t_c$:

$$t_c=5.4\left(\frac{L}{S^{0.5}}\right)^{0.75}$$

L is basin length, and S is slope/relief. It's weird, yet I'm not surprised since it's empirical. Evidently the 5.4 has dimensions of $time$ and $length^{-0.75}$. It's hard to imagine that this equation would actually be useful.