@article{20425, author = "Wyrzykowski, T. and IUGG - IAG, 15th General Assembly Moscow, 1 - 14 August 1971", title = "Non - Univocality of up to Date Systematic error Evalution in Precise Levelling at Various average lengths of mean straight lines or Levelling lines proposal of a new evaluation mode of this Error ", note = "1 s.", }