Quizá quiso decir: Ensayos ; 381. Ensayos ; 383. Comunicación 38. Población ; 38/2007. Recerca ; 38. Población ; 38/2007. Subcellular Biochemistry, 0306-0225 ; 38 Springer Tracts in Modern Physics, 0081-3869 ; 207 Theory and Decision Library C:, Series C: Game Theory, Mathematical Programming and Operations Research, 0924-6126 ; 38 Modern Aspects of Electrochemistry, 0076-9924 ; 38 Springer Tracts in Modern Physics, 0081-3869 ; 212 Springer Tracts in Modern Physics, 0081-3869 ; 218 ATMOSPHERIC AND OCEANOGRAPHIC SCIENCES LIBRARY, 1383-8601 ; 38 Operations Research/Computer Science Interfaces Series, 1387-666X ; 38 Advances in Information Security, 1568-2633 ; 38 Springer Tracts in Modern Physics, 0081-3869 ; 230 Springer Optimization and Its Applications, 1931-6828 ; 38 Advances in Database Systems, 1386-2944 ; 38 Lecture Notes in Control and Information Sciences, 0170-8643 ; 383 Nato Science Series: IV: Earth and Environmental Sciences, 1568-1238 ; 38