1. ISO 17123-2:2001. Optics and optical instruments - Field procedures for testing geodetic and surveying instruments. International Organization for Standardization, Geneva, Switzerland.
2. ISO 12858-1:2014. Optics and optical instruments — Ancillary devices for geodetic instruments — Part 1: Invar levelling staffs. International Organization for Standardization, Geneva, Switzerland.
3. Instrumentenuntersuchungdes Oigitalnivelliers SDL30 von Sokkia;Staiger;AVN,2002
4. M. Takalo, P. Rouhiainen, P. Lehmuskoski, V. Saaranen, On the Systematic Behaviour of the Digital Levelling System Zeiss DiNi12. FIG XXII International Congress, Washington, D.C. USA (2002).
5. A calibration system for Barcode Staves;Klinge;J. Spatial Sci.,2004