O tym, jak
nietoperze obaliły teorię względności (How bats have proved
the theory of relativity to be wrong; an article in Polish; pdf
format) 
Laudatio
for Roger Penrose on the occasion of  conferring on him
the title of Doctor Honoris Causa of Warsaw University (29 
August 2005); pdf file
Spinory
i twistory (transparencje do referatu na seminarium, 20 i 27
lutego 2009) 
Algebry
Clifforda i spinory (transparencje do referatu 26 lutego
2010)  
Ostatnie
publikacje w formacie ps lub pdf / Recent publications in ps or pdf
format 
Geometric aspects
of spinors 
Generalized
pure spinors (co-author: K. Trautman) 
Pin
structures and the modified Dirac operator (co-authors: M. Cahen
and S. Gutt) 
Clifford
and the `square root' ideas
Excerpts 
from my old lectures on spinors 
Pythagorean
spinors and Penrose twistors 
Reflections
and spinors on manifolds 
Relativistic
gravitational fields with close Newtonian analogs (co-authors: P.
Nurowski and E. Schucking) 
On
complex structures in physics 
Gauge
and optical aspects of gravitation 
Spin
spaces, Lipschitz groups and spinor bundles (co-author: Th.
Friedrich) 
Double
covers of pseudo-orthogonal groups 
Robinson
manifolds as the Lorentzian analogs of Hermite manifolds (co-author:
P. Nurowski)
Robinson
manifolds and Cauchy-Riemann spaces 
Robinson
manifolds and the shear-free condition 
Two
approaches to spinor fields (transparencies for talk at Peter G.
Bergmann Memorial Symposium)
Clifford
algebras and their representations 
The
Einstein-Cartan theory 
The
Dirac operator on hypersurfaces 
On
eight kinds of spinors 
Connections
and the Dirac operator on spinor bundles
Remarks
on the history of Lie differentiation
Myron
Mathisson: what little we know of his life (co-author: Tilman
Sauer)
Transparencies
for a talk on twistors (given at the Conference "On the Road
to Reality with Roger Penrose" Warszawa 17 May
2010)
Transparencies
for the talk "Compatibility of conformal and projective
structures on manifolds" (Warszawa 12 April 2013)
A few
oldies: 
On
the conservation theorems and equations of motion in covariant field
theories (scan of a 1956 paper) 
Invariance
properties of physical theories (pdf file with the text in French
of a conference given in 1963 at the College de France) 
Sol's
of Maxwell and Yang-Mills Eqs Associated with Hopf Fibrings (1977
paper) 
Yang-Mills
theory and gravitation: a comparison (pdf file from LNM 926
(1981)) 
Comparison
of Newtonian and Relativistic Theories of Space-Time (scan of a
1964 paper) 
A
simple proof of the Robinson theorem (text of talk given at
Journees Relativistes 1983) 
Optical
geometry (paper with Ivor Robinson, presented at a conference in
1988)