\newcommand{\etalchar}[1]{$^{#1}$}
\ifx\undefined\bysame
\newcommand{\bysame}{\leavevmode\hbox to3em{\hrulefill}\,}
\fi
\begin{thebibliography}{GHMR83}

\bibitem[Art80]{Art}
A.~M. Arthurs, {\em Complementary variational principles}, 2nd ed., Clarendon,
  Oxford, 1980.

\bibitem[AVGZ82]{AVG1}
V.~L. Arnol{\cprime}d, A.~N. Varchenko, and S.~M. Gusein-Zade, {\em
  Singularities of differentiable maps. \rom{I}}, ``Nauka'', Moscow, 1982
  (Russian), English transl., Birkh\"auser, Basel, 1985.

\bibitem[AVGZ84]{AVG2}
V.~L. Arnol{\cprime}d, A.~N. Varchenko, and S.~M. Gusein-Zade, {\em
  Singularities of differentiable maps. \rom{II}}, ``Nauka'', Moscow, 1984
  (Russian), English transl., Birkh\"auser, Basel, 1988.

\bibitem[BCW82]{BCW}
H.~Bass, E.~H. Connell, and D.~Wright, {\em The {J}acobian conjecture}, Bull.
  Amer. Math. Soc. {\bf 7} (1982), 287--330.

\bibitem[Ber70]{Ber}
V.~I. Berdichevski\u\i, {\em A variational equation of continuum mechanics},
  Problems of the Mechanics of a Solid Deformable Body (L.~I. Sedov and Yu.~N.
  Robotnov, eds.), ``Sudostroenie'', Leningrad, 1970, (V. V. Novozhilov
  Sixtieth Birthday Vol.), pp.~55--66 (Russian).

\bibitem[BM85]{BM}
H.~Bass and G.~H. Meisters, {\em Polynomial flows in the plane}, Adv. in Math.
  {\bf 55} (1985), 173--203.

\bibitem[C{\etalchar{+}}80]{Cot}
R.~W. Cottle et~al. (eds.), {\em Variational inequalities and complementarity
  problems}, Proc. Internat. School (Erice, 1978), Wiley, New York, 1980.

\bibitem[Coo88]{Coo1}
B.~Coomes, {\em Polynomial flows, symmetry groups, and conditions sufficient
  for injectivity of maps}, Ph.D. thesis, Univ. Nebraska--Lincoln, 1988.

\bibitem[Cooar]{Coo2}
B.~Coomes, {\em The {L}orenz system does not have a polynomial flow}, J.
  Differential Equations (to appear).

\bibitem[For86]{For}
E.~Formanek, {\em Generating the ring of matrix invariants}, Lecture Notes in
  Math., vol. 1197, Springer-Verlag, Berlin and New York, 1986, pp.~73--82.

\bibitem[Gab72]{Gab}
P.~Gabriel, {\em Unzerlegbare {D}arstellungen. \rom{II}}, Manuscripta Math.
  {\bf 6} (1972), 71--103.

\bibitem[GHMR83]{GHMR}
J.~Guckenheimer, P.~Holmes, M.~Martineau, and L.~P. Robinson, {\em Nonlinear
  oscillations, dynamical systems, and bifurcations of vector fields},
  Springer-Verlag, New York, 1983.

\bibitem[HM86]{HM}
S.~I. Hariharan and T.~H. Moulton (eds.), {\em Numerical methods for partial
  differential equations}, Longman, New York, 1986.

\bibitem[HSar]{HS}
J.~K. Hunter and J.~Scheurie, {\em Perturbed solitary wave solutions of a model
  equation for water waves}, Physica D (to appear).

\bibitem[Lio60]{Lio}
J.~L. Lions, {\em Probl\`emes mixtes abstraits}, Proc. Internat. Congr. Math.
  (Edinburgh, 1958), Cambridge Univ. Press, London and New York, 1960,
  pp.~389--397.

\bibitem[LL83]{LL}
P.~D. Lax and C.~D. Levermore, {\em The small dispersion limit for the {KdV}
  equation. \rom{I (overview)}, \rom{II}, \rom{III}}, Comm. Pure Appl. Math.
  {\bf 36} (1983), 253--290, 571--594, 809--829.

\bibitem[Mar]{Mar}
A.~E. Martynyuk, {\em Some approximate methods for solving nonlinear equations
  with unbounded operators}, Izv. Vyssh. Uchebn. Zaved. Mat. {\bf 1966},
  no.~6(55), 85--94 (Russian), addendum, ibid. {\bf 1967} no. 8(63), 111.

\bibitem[Mei82]{Mei1}
G.~H. Meisters, {\em Jacobian problems in differential equations and algebraic
  geometry}, Rocky Mountain J. Math. {\bf 12} (1982), 679--705.

\bibitem[Meiar]{Mei2}
G.~H. Meisters, {\em Polynomial flows on {$\bold R^n$}}, Proc. Semester on
  Dynamical Systems (Warsaw, Autumn 1986), Springer-Verlag, Berlin, Heidelberg,
  and New York, (to appear).

\bibitem[MO87]{MO}
G.~H. Meisters and C.~Olech, {\em A poly-flow formulation of the {J}acobian
  conjecture}, Bull. Acad. Polon. Sci. S\'er. Sci. Math. {\bf 35} (1987),
  725--731.

\bibitem[Osh86]{osh}
S.~Osher, {\em Shock capturing algorithms for equations of mixed type},
  Numerical Methods for Partial Differential Equations (S.~I. Hariharan and
  T.~H. Moulton, eds.), Longman, New York, 1986, pp.~305--322.

\bibitem[Ost78]{Ost}
L.~A. Ostrovsky, {\em Nonlinear internal waves in a rotating ocean. \rom{Part
  2}}, Oceanology {\bf 18} (1978), 181--191.

\bibitem[Pet86]{Pet}
G.~S. Petrov, {\em Elliptic integrals and their nonoscillatory behavior},
  Funktsional. Anal. i Pri\-lo\-zhen. {\bf 20} (1986), 46--49 (Russian),
  English transl. in Functional Anal. Appl. {\bf 20} (1986).

\bibitem[Slo58]{Slo}
L.~N. Slobodetski\u\i, {\em Generalized {S}obolev spaces and their application
  to boundary value problems for partial differential equations}, Leningrad.
  Gos. Ped. Inst. Uchen. Zap. {\bf 197} (1958), 54--112 (Russian), English
  transl. in Amer. Math. Soc. Transl. (2) {\bf 57} (1966).

\bibitem[Spi90]{Spi}
M.~D. Spivak, {\em The joy of {\TeX}}, 2nd revised ed., Amer. Math. Soc.,
  Providence, R.~I., 1990.

\end{thebibliography}