Uncertainties in the Analysis of Avoa for Determination of Fracture Orientation H. Houllevigue, S. Harwood, P. S. Rowbotham, I. Bush, P. R. Williamson and J. M. Kendall Rev. Inst. Fr. Pét., 53 5 (1998) 621-627 Published online: 01 December 2006 DOI: 10.2516/ogst:1998056