Snijder, Ronald (2010). „The Profits of Free Books: An Experiment to Measure the Impact of Open Access Publishing”. Learned Publishing. 23 (4): 293—301. ISSN0953-1513. doi:10.1087/20100403.
Snijder, Ronald (2010). „The Profits of Free Books: An Experiment to Measure the Impact of Open Access Publishing”. Learned Publishing. 23 (4): 293—301. ISSN0953-1513. doi:10.1087/20100403.