@article{Amaral1998,
title={Power law scaling for a system of interacting units with complex internal structure},
author={Amaral LAN, 
Buldyrev SV, 
Havlin S, 
Salinger MA, 
Stanley HE},
abstract={We study the dynamics of a system composed of interacting units each with a complex internal structure comprising many subunits and treat the case in which each subunit grows in a multiplicative manner. We propose a model for such systems in which the interaction among the units is treated in a mean field approximation and the interaction among subunits is nonlinear. We test the model and find agreement between our predictions and empirical results based on a large economics database spanning 20 years.},
journal={Physical Review Letters},
volume={80},
doi={https://doi.org/10.1103/PhysRevLett.80.1385},
year={1998},
month={FEB},
day={16},
pages={1385--1388},
}