1.

D.E. Alspach, Quotients of $c_0$ are almost isometric to subspaces of $c_0$, Proc. Amer. Math. Soc. 76 (1979) 285–289.  MR537089 D.E. Alspach, Quotients of $c_0$ are almost isometric to subspaces of $c_0$, Proc. Amer. Math. Soc. 76 (1979) 285–289.  MR537089

2.

A. Avilés, F. Cabello, J.M.F. Castillo, M. González, Y. Moreno, Separably injective Banach spaces. Lecture Notes in Math. 2132, Springer; in press.  MR3003929 10.1016/j.aim.2012.10.013 A. Avilés, F. Cabello, J.M.F. Castillo, M. González, Y. Moreno, Separably injective Banach spaces. Lecture Notes in Math. 2132, Springer; in press.  MR3003929 10.1016/j.aim.2012.10.013

3.

J. Bourgain, A counterexample to a complementation problem, Compo. Math. 43 (1981) 133–144.  MR631431 J. Bourgain, A counterexample to a complementation problem, Compo. Math. 43 (1981) 133–144.  MR631431

4.

J. Bourgain and G. Pisier, A construction of ${\mathcal L}_\infty$-spaces and related Banach spaces, Bol. Soc. Bras. Mat. 14 (1983) 109–123.  MR756904 10.1007/BF02584862 J. Bourgain and G. Pisier, A construction of ${\mathcal L}_\infty$-spaces and related Banach spaces, Bol. Soc. Bras. Mat. 14 (1983) 109–123.  MR756904 10.1007/BF02584862

5.

Y.A. Brudnyi, and N. J. Kalton, Polynomial approximation on convex subsets of $R\sp n$. Constr. Approx. 16 (2000) 161–199.  MR1735240 10.1007/s003659910008 Y.A. Brudnyi, and N. J. Kalton, Polynomial approximation on convex subsets of $R\sp n$. Constr. Approx. 16 (2000) 161–199.  MR1735240 10.1007/s003659910008

6.

F. Cabello Sánchez and J.M.F. Castillo, Uniform boundedness and twisted sums of Banach spaces, Houston J. Math. 30 (2004) 523–536.  MR2084916 F. Cabello Sánchez and J.M.F. Castillo, Uniform boundedness and twisted sums of Banach spaces, Houston J. Math. 30 (2004) 523–536.  MR2084916

7.

F. Cabello Sánchez, J.M.F. Castillo, N.J. Kalton and D.T. Yost, Twisted sums with $C(K)$ spaces, Trans. Amer. Math. Soc. 355 (2003) 4523–4541.  MR1990760 10.1090/S0002-9947-03-03152-0 F. Cabello Sánchez, J.M.F. Castillo, N.J. Kalton and D.T. Yost, Twisted sums with $C(K)$ spaces, Trans. Amer. Math. Soc. 355 (2003) 4523–4541.  MR1990760 10.1090/S0002-9947-03-03152-0

8.

J.M.F. Castillo, Banach spaces, à la recherche du temps perdu, Extracta Math. 15 (2000) 291-334.  MR1823897 J.M.F. Castillo, Banach spaces, à la recherche du temps perdu, Extracta Math. 15 (2000) 291-334.  MR1823897

9.

J.M.F. Castillo and M. González, Three-space problems in Banach space theory, Lecture Notes in Math. 1667 (1997), Springer. MR1482801 J.M.F. Castillo and M. González, Three-space problems in Banach space theory, Lecture Notes in Math. 1667 (1997), Springer. MR1482801

10.

J.M.F. Castillo and Y. Moreno, On the Lindenstrauss-Rosenthal theorem, Israel J. Math. 140 (2004) 253–270. MR2054847 10.1007/BF02786635 J.M.F. Castillo and Y. Moreno, On the Lindenstrauss-Rosenthal theorem, Israel J. Math. 140 (2004) 253–270. MR2054847 10.1007/BF02786635

11.

J.M.F. Castillo and A. Plichko, Banach spaces in various positions. J. Funct. Anal. 259 (2010) 2098-2138.  MR2671123 10.1016/j.jfa.2010.06.013 J.M.F. Castillo and A. Plichko, Banach spaces in various positions. J. Funct. Anal. 259 (2010) 2098-2138.  MR2671123 10.1016/j.jfa.2010.06.013

12.

W.B. Johnson and J. Lindenstrauss, Examples of $\mathcal L_1$ spaces, Ark. Mat. 18 (1980) 101–106.  MR608329 W.B. Johnson and J. Lindenstrauss, Examples of $\mathcal L_1$ spaces, Ark. Mat. 18 (1980) 101–106.  MR608329

13.

N.J. Kalton, On subspaces of $c_0$ and extension of operators into $C(K)$-spaces, Q. J. Oxford 52 (2001) 313-328.  MR1865904 10.1093/qjmath/52.3.313 N.J. Kalton, On subspaces of $c_0$ and extension of operators into $C(K)$-spaces, Q. J. Oxford 52 (2001) 313-328.  MR1865904 10.1093/qjmath/52.3.313

14.

N.J. Kalton, Extension of linear operators and Lipschitz maps into $\mathcal{C}(K)$-spaces, New York J. Math. 13 (2007) 317–381. MR2357718 N.J. Kalton, Extension of linear operators and Lipschitz maps into $\mathcal{C}(K)$-spaces, New York J. Math. 13 (2007) 317–381. MR2357718

15.

N. Kalton, Automorphisms of $\mathcal{C}(K)$ spaces and extension of linear operators, Illinois J. Math. 52 (2008) 279–317. MR2507245 euclid.ijm/1242414132 N. Kalton, Automorphisms of $\mathcal{C}(K)$ spaces and extension of linear operators, Illinois J. Math. 52 (2008) 279–317. MR2507245 euclid.ijm/1242414132

16.

N.J. Kalton, A. Pełczyński, Kernels of surjections from $\mathcal L_1$-spaces with an application to Sidon sets, Math. Ann. 309 (1997) 135–158.  MR1467651 10.1007/s002080050107 N.J. Kalton, A. Pełczyński, Kernels of surjections from $\mathcal L_1$-spaces with an application to Sidon sets, Math. Ann. 309 (1997) 135–158.  MR1467651 10.1007/s002080050107

17.

J. Lindenstrauss, On a certain subspace of $l_1$, Bull. Polish Acad. Sci. 12 (1964) 539-542.  MR174963 J. Lindenstrauss, On a certain subspace of $l_1$, Bull. Polish Acad. Sci. 12 (1964) 539-542.  MR174963

18.

J. Lindenstrauss, A remark on $\mathcal L_1$-spaces Israel J. Math. 8 (1970), 80-82.  MR259582 10.1007/BF02771554 J. Lindenstrauss, A remark on $\mathcal L_1$-spaces Israel J. Math. 8 (1970), 80-82.  MR259582 10.1007/BF02771554

19.

J. Lindenstrauss and L. Tzafriri, Classical Banach spaces I, Springer-Verlag, Berlin 1977.  MR500056 J. Lindenstrauss and L. Tzafriri, Classical Banach spaces I, Springer-Verlag, Berlin 1977.  MR500056

20.

Y. Moreno, The diagonal functors, Appl. Cat. Struct. 16 (2008) 617–627.  MR2448146 10.1007/s10485-007-9074-7 Y. Moreno, The diagonal functors, Appl. Cat. Struct. 16 (2008) 617–627.  MR2448146 10.1007/s10485-007-9074-7

21.

A. Pełczyński, personal communication. A. Pełczyński, personal communication.