1. NR/L3/TRK/0030 Iss. 1, Reinstatement of Absolute Track Geometry (WCRL Routes), Network Rail 2008
https://standards.globalspec.com/std/10216330/nr-l3-trk-0030
2. BS EN 13803:2017 Railway Applications–Track–Track Alignment Design Parameters–Track Gauges 1435 mm and Wider. CEN
https://shop.bsigroup.com/ProductDetail/?pid=000000000030279796
3. The Swiss Trolley- A Modular System for Track Surveying
https://www.sgc.ethz.ch/publications.html