Luc Anselin's article on GeoDa is the most cited "classic paper" (published in 2006) in the Social Sciences category of Geography & Cartography. According to Google Scholar, 1,411 people cited the article "GeoDa: an introduction to spatial data analysis" Luc Anselin co-authored with I. Syabri and Y. Kho in Geographical Analysis. Congratulations!
Also according to Google Scholar, over 7,600 publications are referencing GeoDa. Many of these publications address empirical research challenges using the exploratory spatial data analysis and spatial regression methods of the software.