Quizá quiso decir: Springer Tracts in Modern Physics, 0081-3869 ; 207 IFIP International Federation for Information Processing, 1571-5736 ; 207 NATO Science Series II: Mathematics, Physics and Chemistry, 1568-2609 ; 207 Reviews of Environmental Contamination and Toxicology, Continuation of Residue Reviews, 0179-5953 ; 207 Lecture Notes in Electrical Engineering, 1876-1100 ; 207 Lecture Notes in Mathematics, 0075-8434 ; 2070 Operator Theory Advances and Applications ; 207 Lecture Notes in Mathematics, 0075-8434 ; 2078 Lecture Notes in Mathematics, 0075-8434 ; 2077 Studies in Fuzziness and Soft Computing, 1434-9922 ; 207 Advances in Polymer Science, 0065-3195 ; 207 Lecture Notes in Computer Science, 1861-2075 ; 4780 Ecological Studies, Analysis and Synthesis, 0070-8356 ; 207 Studies in Computational Intelligence, 1860-949X ; 207 Advances in Anatomy, Embryology and Cell Biology, 0301-5556 ; 207 Lecture Notes in Statistics, 0930-0325 ; 207 Handbook of Experimental Pharmacology, 0171-2004 ; 207 Lecture Notes in Mathematics, 0075-8434 ; 2071 Lecture Notes in Mathematics, 0075-8434 ; 2072 Lecture Notes in Mathematics, 0075-8434 ; 2073