JANSEN, B. J. ., A. . SPINK, and J. . PEDERSEN. “THE EFFECT OF SPECIALIZED MULTIMEDIA COLLECTIONS ON WEB SEARCHING”. Journal of Web Engineering, vol. 3, no. 3-4, Aug. 2004, pp. 182-99, https://journals.riverpublishers.com/index.php/JWE/article/view/4305.