@book{Giles_1987, address={Cambridge}, title={Introduction to the analysis of metric spaces}, volume={Australian Mathematical Society lecture series}, publisher={Cambridge University Press}, author={Giles, J. R.}, year={1987} }
@book{Kreyszig_1989, address={New York}, edition={Wiley Classics Library ed}, title={Introductory functional analysis with applications}, volume={Wiley classics library}, publisher={Wiley}, author={Kreyszig, Erwin}, year={1989} }
@book{Young_1988, address={Cambridge}, title={An introduction to Hilbert space}, url={https://eu.alma.exlibrisgroup.com/view/action/uresolver.do?operation=resolveService&package_service_id=5029053650002418&institutionId=2418&customerId=2415}, publisher={Cambridge University Press}, author={Young, Nicholas}, year={1988} }
