I cannot find the following 4 papers by _Sekiguchi–Suwa_ in their works on _Kummer–Artin–Schreier–Witt theory_:

1. _On the unified Kummer–Artin–Schreier–Witt theory_, Prépublications du laboratoire de Mathématiques Pures de Bordeaux, Prépublication nº 111 (1999).
2. _On the unified Kummer–Artin–Schreier–Witt sequences_
3. _Théories de Kummer–Artin–Schreier–Witt_,  C. R. Acad. Sci. Paris 319 (1994), 105-110.
4. _Theorie de Kummer–Artin–Schreier_, C. R. Acad.
Sci. Paris 312 (1991), 417-420.

I will be very happy if someone can help me.

Thanks.