Rodrí­guez-Yunta, Luis. “Buying Articles on the Internet and Open Access Policies: Could Journal Subscriptions Be Replaced by Pay-Per-View Access?”. Anuario ThinkEPI, vol. 6, Oct. 2012, pp. 197-9, https://thinkepi.scimagoepi.com/index.php/ThinkEPI/article/view/30419.