JOURNAL OF MATHEMATICAL SYSTEMS,
                     ESTIMATION, AND CONTROL

Contributors and readers are reminded that, beginning with Volume
Four, JMSEC begins its transition to a partially electronic
format.  Specifically, after the transition, each issue will
carry a number of four page, extended summaries.  There will in
the future be between 15-20 such summaries per issue.  The FULL
paper will be available only electronically via anonymous ftp.
For access, the full ftp address is required along with the
article identification number which is carried on the first page
of the extended summary.  For the time being, copies of the full
electronic version will be free of charge.  More details are
included in the Editorial in Volume 4#1 or directly from the
publisher, Birkhaeuser Boston, 675 Massachusetts Avenue,
Cambridge, MA 02139.  Also, see e-mail address above.

Volume Four, Number Two

An Application of Luenberger's Shuffle Algorithm to
Regularization of Descriptor Systems by Proportional Feedback
          V. Lovass-Nagy, R. Mukundan and R.J. Schilling

Towards Robustness and Genericity of Dynamic Feedback
Linearization
     Krysztof Tcho/'n

Finite Dimensional Filters with Nonlinear Drift I:  A class of
filters including both Kalman-Bucy filters and Benes filters
          Stephen S.-T. Yau

On Discontinous Strategies in Optimal Control Problems
          D. B. Silin

A Convergence Theory for Fully Galerkin Approximations of
Parabolic PDE in Inverse Problems
          J.G. Wade

SUMMARY:  Design of Finite-Dimensional Controllers for Infinite-
dimensional Systems by Approximation
          K.A. Morris

SUMMARY:  Fixed Gain Off-line Estimators of ARMA Parameters
          L/'aszl/'o Gerencs/'er

SUMMARY:  Extended Controller Form and Invariants of Nonlinear
Control Systems with a Single Input
          Wei Kang

SUMMARY:  Necessary Condition and Genericity of Dynamic Feedback
Linearization
          P. Rouchon


Due to a processing error at the publisher's, we omitted in these
two issues of the Journal the specific information required to
order electronic copies of papers whose Summaries have appeared.
That information will be included in future issues but is given
below for those who may have immediate need.

___________________________________________________________
Articles appearing in SUMMARY form are available in COMPLETE form
by anonymous ftp.  Please follow these instructions:

    ADDRESS:     trick.ntp.springer.de
    USER:        anonymous (personal e-mail address)
    ACCESS:      cd jmsec
                 get ID#.ps

The ID # is the five digit identification number of the paper
desired.  It is located at the bottom of the first page of the
Summary and is called "Retrieval Code."