http://potterlab.bme.gatech.edu/development-data/simple-text/daily/spont/sparse/5-3-28.spk.txt.bz2
http://potterlab.bme.gatech.edu/development-data/simple-text/daily/spont/sparse/6-1-28.spk.txt.bz2
http://potterlab.bme.gatech.edu/development-data/simple-text/daily/spont/sparse/6-2-28.spk.txt.bz2
http://potterlab.bme.gatech.edu/development-data/simple-text/daily/spont/sparse/6-3-28.spk.txt.bz2