The theory of infinite soluble groups অনুযায়ী Lennox, John C., Robinson, Derek J. S.

Available for University of the Philippines Diliman via Oxford Scholarship Online. Click here to access:

The theory of infinite soluble groups অনুযায়ী Lennox, John C., Robinson, Derek John Scott

Available for University of the Philippines System via Oxford Scholarship Online. Click here to access.

Finite soluble groups. অনুযায়ী Doerk, Klaus

On products of normal supersoluble subgroups and generalisations অনুযায়ী Perez, Edmundo R.

On equioptimal groups অনুযায়ী Petalcorin, Gaudencio C. 1965-