<ul><li><a href=http://www.legislation.gov.uk/ukpga/1993/43 target=_blank>Railways Act 1993(last updated in January, 2022, Sections 4, 8 )</a></li><li><a href=https://www.legislation.gov.uk/uksi/2019/700/contents/made target=_blank>The Railway (Licensing of Railway Undertakings) (Amendment etc.) (EU Exit) Regulations 2019( The Railway (Licensing of Railway Undertakings) (Amendment etc.) (EU Exit) Regulations 2019, UK SI 2019 No. 700)</a></li><li><a href=https://www.orr.gov.uk/guidance-compliance/rail/operator-licences-exemptions/how-apply-licence-or-licence-exemption target=_blank>Office of Rail and Road 's website(last consulted in May 2022)</a></li></ul>