The dataset for Abramoff, et al. PLOSOne 2014 can be used and downloaded for non-commercial scientific research by filling out the form linked here. Once you have completed and submitted the form, you will be given the link for downloading.
citation: Abrà moff MD, Wu X, Lee K, Tang L (2014) Subvoxel Accurate Graph Search Using Non-Euclidean Graph Space. PLoS ONE 9(10): e107763. doi:10.1371/journal.pone.0107763