1. STN EN 286-1 (01 4201): 2010 Geometrical Product Specifications (GPS). ISO code system for tolerances of linear sizes. Part 1: Basics of tolerances, deviations and fits.
4. HUMIENNY, Z. et al. 2001. Geometrical Product Specifications: Course for Technical Universities. Poland / Warsaw: Warsaw University of Technology Printing House, 289 p. ISBN 83-912190-8-9
5. STN EN ISO 2692 (01 4403): 2007 Geometrical product specifications (GPS). Geometric tolerancing. Maximum material requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR).