[AC]

P. R. Ahern and D. N. Clark, On inner functions with H

^{p}-derivative, Michigan Math. J., 21 (1974), 115–127.

Google Scholar[B1]

J. A. Ball, Interpolation problems of Pick-Nevanlinna and Loewner types for meromorphic matrix functions, Integral Equations and Operator Theory, 6 (1983), 804–840.

Google Scholar[B2]

J. A. Ball, Invariant subspace representations, unitary interpolants and factorization indices, Topics in Operator Theory Systems and Networks (OT12), Birkhäuser Verlag, to appear.

[BH1]

J. A. Ball and J. W. Helton, A Beurling-Lax theorem for the Lie group U(m,n) which contains most classical interpolation theory, J. Operator Theory, 9 (1983), 107–142.

Google Scholar[BH2]

J. A. Ball and J. W. Helton, Factorization results related to shifts in an indefinite metric, Integral Equations and Operator Theory, 5 (1982), 632–658.

Google Scholar[BH3]

J. A. Ball and J. W. Helton, Beurling-Lax representations using classical Lie groups with many applications II: GL(n, ⊄) and Wiener-Hopf factorization, Integral Equations and Operator Theory. 7 (1984), 291–309.

Google Scholar[BH4]

J. A. Ball and J. W. Helton, Beurling-Lax representations using classical Lie groups with many applications III: groups preserving two bilinear forms, to appear in Amer. J. Math.

[BH5]

J. A. Ball and J. W. Helton, Beurling-Lax representations using classical Lie groups with many applications IV: GL(n,R), U^{*}(2n), SL(n, ⊄) and a solvable group, to appear.

[Bog]

J. Bognar, Indefinite Inner Product Spaces, Springer-Verlag, 1974.

[C]

C. Caratheodory, Theory of Functions of a Complex Variable, Vol. 2, Chelsea, 1954.

[CG]

K. Clancey and I. Gohberg, Factorization of Matrix Functions and Singular Integral Operators (OT 3), Birkhäuser Verlag, 1981.

[DD]

P. Dewilde and H. Dym, Lossless inverse scattering for digital filters: theory and applications, to appear.

[H1]

J. W. Helton, Orbit structure of the Möbius transformations semigroup acting on H^{∞} (broadband matching), in Topics in Functional Analysis, Advances in Math. Suppl. Studies 3, 129–257, Academic Press, 1978.

[H2]

J. W. Helton, The distance of a function to H

^{∞} in the Poincaré distance; electrical power transfer, J. Functional Analysis, 38 (1980), 273–314.

Google Scholar[H3]

J. W. Helton, A simple test to determine gain bandwidth limitations, Proc. IEEE International Conference Circuit Theory, Phoenix, 1977.

[Hof]

K. Hoffman, Banach Spaces of Analytic Functions, Prentice, Hall, 1962.

[K]

T. Kato, Perturbation Theory of Linear Operations, Springer-Verlag, 1966.

[L]

K. Loewner, Uber monotone Matrix Funktionen, Math. Z., 38 (1934), 177–216.

Google Scholar[M]

D. E. Marshall, An elementary proof of the Pick-Nevanlinna interpolation theorem, Mich. Math. J., 21 (1974), 219–223.

Google Scholar[NF]

B. Sz.-Nagy and C. Foias, Harmonic Analysis of Operators on Hilbert Space, American Elsevier, 1970.

[NK]

B. Sz.-Nagy and A. Koranyi, Relations d'un probleme de Nevanlinna-Pick avec la theorie des operateurs de l'espace Hilbertian, Acta Math. Acad. Sci. Hungar., 7 (1956), 295–302.

Google Scholar[Nh]

Z. Nehari, On bounded bilinear forms, Ann. of Math., 65 (1957), 153–162.

Google Scholar[N1]

R. Nevanlinna, Uber Beschränkte analytische Funktionen, Ann. Acad. Sci. Fenn., Ser. A, 32, No. 7 (1929)

Google Scholar[N2]

R. Nevanlinna, Analytic Functions, Springer, 1970.

[P]

R. S. Phillips, On dissipative operators, in “Lecture Series in Differential Equations,” Vol. II (A. K. Aziz, ed.) von Nostrand, 1969, pp. 65–113.

[RR]

M. Rosenblum and J. Rovnyak, An operator-theoretic approach to theorems of Pick-Nevanlinna and Loewner types I, Integral Equations and Operator Theory, 3 (1980), 408–436.

Google Scholar[S]

D. Sarason, Generalized Interpolation in H

^{∞}, Trans. Amer. Math. Soc., 127 (1967), 179–203.

Google Scholar