Sancho R. Indicadores bibliométricos utilizados en la evaluación de la ciencia y la tecnología. Rev Esp Doc Cient 1990;13(3-4):842-65. 
Solla Price DJ de. Hacia una ciencia de la ciencia. Barcelona: Ariel, 1973:128. 
Garfield E. Which medical journals have the greatest impact? Ann Intern Med 1986;105(2):313-20. 
Oppenheim C, Renn SP. Highly cited old paper and the reasons why they continue to be cited J Am Soc Inf Sci 1978;29:226-30. 
Brooks TA. Evidence of complex citer motivations. J Am Soc Inf Sci 1986;37(1):34-6. 
Moravcsik MJ, Morugesan P. Some results on the function and quality of citation. Soc Stud of Sci 1975;5:86-92. 
Spiegel-Rüsing I. Highly cited old papers and the reasons why they continue to be cited. Soc Stud Sci 1977;7:105. 
Vinkler P. A quasi-quantitative citation model. Scientometrics 1987;12(1-2):47-72. 
Shaw JG. Article-by-article citation analysis of medical journals. Scientometrics 1987;12(1-2):101-10. 
Spodick DH, Goldberg J. The editor’s correspondence: analysis of patterns appearing in selected specialty and general journals. Am J Cardiol 1983;52:1290-3. 
Bonzi S. Characteristics of a literature as predictors of relatedness between cited and citing works. Am Soc Inform Sci 1982;33(4):208-16.