1. Zhang, F. (1999). Matrix Theory: Basic Results and Techniques Springer. A standard modern reference on matrices; contains a good chapter on Hermitian matrices
2. Witten, I. H., A. Moffat and T. C. Bell (1994). Managing Gigabytes – Compressing and Indexing Documents and Images Van Nostrand Reinhold. A useful book about the nuts and bolts of IR. There is now a second edition published in 1999
3. Wootters, W. K. (1980b). ‘Information is maximised in photon polarization measurements.’ In Quantum Theory and Gravitation. A. R. Marlow (ed.). Academic Press, pp. 13–26. A self-contained account of a central idea described in the thesis by Wootters (1980a). His idea is used in the Prologue of GIR
4. Zeller, Eduard (1888). Plato and the Older Academy, translated by Sarah Alleyne and Alfred Goodwin, Longmens, Green and Co., pp. 21–22, note 41
5. Wootters, W. K. (1980a). The Acquisition of Information from Quantum Measurements. Center for Theoretical Physics, Austin, The University of Texas at Austin. Wootters summarises his results in this thesis by ‘… the observer's ability to distinguish one state from another seems to be reflected in the structure of quantum mechanics itself’. He gives an information-theoretic argument for a particular form of a probabilistic law which is used in the Prologue of this book