\begin{thebibliography}{Wri73b}

\bibitem[CH67]{CH}
R.~W. Carter and T.~O. Hawkes.
\newblock The {$\F$}-normalizers of a finite soluble group.
\newblock {\em J. Alg.}, 5:175 -- 201, 1967.

\bibitem[DH92]{DH}
K.~Doerk and T.~O. Hawkes.
\newblock {\em Finite soluble groups}.
\newblock Walter de Gruyter, 1992.

\bibitem[EW]{EW}
B.~Eick and C.~R.~B. Wright.
\newblock Computing subgroups by exhibition in finite solvable groups.
\newblock To appear in J. Symbolic Comp.

\bibitem[Gas63]{G}
W.~Gasch\"utz.
\newblock Zur theorie der endlichen aufl\"osbaren gruppen.
\newblock {\em Math. Z.}, 80:300 -- 305, 1963.

\bibitem[Wri73a]{WA}
C.~R.~B. Wright.
\newblock An internal approach to covering groups.
\newblock {\em J. Alg.}, 25:128 -- 145, 1973.

\bibitem[Wri73b]{WB}
C.~R.~B. Wright.
\newblock On internal formation theory.
\newblock {\em Math. Z.}, 134:1 -- 9, 1973.

\end{thebibliography}