JOURNAL OF URBAN TECHNOLOGY7 Period11992-2006 ，Period22007-20091 Period3(2010-2012 385 356 350 315 280 : 27H 245 213 210 175 140 LIO7 1sn3nV St 9:E0e [AlSJaAlun Suojoelf leyaueys] 105 70 59 33 35 24-25 2522 9 0200 030 8 Ab Bo Ch Ed Ar Co Gr:Ab Bo Ch Ed Ar Co Gr:Ab Bo Ch Ed Ar Co Gr Ab Abstract Bo Book Ch Book chapter Ed Editorial: Ar Journal article;Co Conference paper,Gr Grey literature Figure 1.Source documents by type and period of publication often contain errors,which can lead to significant variations in the results of their analysis (Adam,2002),all citations were tested for correctness and completeness,so as to guaran- tee the highest degree of data reliability.Altogether,a total of 22,137 citations were col- 花o P lected(957 to source documents and 21,180 to non-source documents),and they were used to build a frequency table showing each cited publication,together with the number of times it had been cited.This made it possible to determine that the total number of cited references was 17,574.Only citations to source documents were con- sidered during the analysis. The First Two Decades of Smart-City Research A New and Fast Growing Research Area The analysis shows that smart city-research established itself as a new area of scientific enquiry in 2009,and since then,it has been fast-growing,arousing strong interest from an expanding scientific community of researchers.This growth is particularly evident when observing the rise in the production of source documents(See Figure 3),which has continued to increase over time,together with the number of researchers involvedoften contain errors, which can lead to significant variations in the results of their analysis (Adam, 2002), all citations were tested for correctness and completeness, so as to guaran￾tee the highest degree of data reliability. Altogether, a total of 22,137 citations were col￾lected (957 to source documents and 21,180 to non-source documents), and they were used to build a frequency table showing each cited publication, together with the number of times it had been cited. This made it possible to determine that the total number of cited references was 17,574. Only citations to source documents were con￾sidered during the analysis. The First Two Decades of Smart-City Research A New and Fast Growing Research Area The analysis shows that smart city-research established itself as a new area of scientific enquiry in 2009, and since then, it has been fast-growing, arousing strong interest from an expanding scientific community of researchers. This growth is particularly evident when observing the rise in the production of source documents (See Figure 3), which has continued to increase over time, together with the number of researchers involved Figure 1. Source documents by type and period of publication JOURNAL OF URBAN TECHNOLOGY 7 Downloaded by [Shanghai Jiaotong University] at 03:36 25 August 2017