Harold Exton is a mathematician at University of Central Lancashire (called Preston Polytechnic while he was there) working on hypergeometric functions, who introduced the Hahn–Exton q-Bessel function.

References

• Exton, Harold (1976), Multiple hypergeometric functions and applications, Mathematics and its applications, Chichester: Ellis Horwood Ltd., ISBN 978-0-470-15190-7, MR 0422713
• Exton, Harold (1978), Handbook of hypergeometric integrals, Mathematics and its Applications, Chichester: Ellis Horwood Ltd., ISBN 978-0-85312-122-0, MR 0474684
• Exton, Harold (1983), q-hypergeometric functions and applications, Ellis Horwood Series: Mathematics and its Applications, Chichester: Ellis Horwood Ltd., ISBN 978-0-85312-491-7, MR 0708496