The tour calculation for Latvia, Estonia and Leningrad Region (to St. Petersburg) based on the book "Europaradweg R1 Euroroute Teil 2" ISBN 978-3-981-0029-2-8.
The tour calculation for St. Petersburg - Helsinki based on the book "Tallinn –
Sankt Petersburg – Helsinki" (R1 Euroroute Teil 2a) ISBN 978-3-9817186-6-9.
