8©L.MORA ET AL Africa (19)America(133),Asia (188),Australia (35).Europe (404) 275 250 237 225 200 175 150 137 125 100 83 LI07 1sn3nV St 9:E0e [ASJaAlun Suojoelf leyueys]Kq papeojuMod 75 53 50 33 26 25 25 25 16 10 15 0 uEdoBu EdGotBu EdGoBuEdo Ed ot B Research and Business;E Research and Education; G Research and Government O Other Figure 2.Organizations by type and location in their development(See Figure 4).Initially,this research area was very small,with only 19 source documents published during the first 10 years of research.Over the following eight years,from the beginning of 2002 to the end of 2009,production increased slightly. During this period 132 documents were published,about 17 per year.The period between 2010 and 2012,instead,was characterized by a tremendous growth in the number of pub- lications.More than 900 new source documents were produced in three years,and they represent approximately 86 percent of the smart-city literature developed during the first two decades of research. Fragmentation of Knowledge All branches of knowledge are composed of large groups of interconnected publications, and their structure can be represented through the use of complex mapping techniques, allowing the scientific community involved in their production to easily grasp "the big picture"(Moya-Anegon et al.,2004):"a spatial representation of the relationship among [...individual papers as reflected in some formal,strictly quantifiable properties of scientific literature at a given time"(De Bellis,2009:142).Citations are the elements thatin their development (See Figure 4). Initially, this research area was very small, with only 19 source documents published during the first 10 years of research. Over the following eight years, from the beginning of 2002 to the end of 2009, production increased slightly. During this period 132 documents were published, about 17 per year. The period between 2010 and 2012, instead, was characterized by a tremendous growth in the number of pub￾lications. More than 900 new source documents were produced in three years, and they represent approximately 86 percent of the smart-city literature developed during the first two decades of research. Fragmentation of Knowledge All branches of knowledge are composed of large groups of interconnected publications, and their structure can be represented through the use of complex mapping techniques, allowing the scientific community involved in their production to easily grasp “the big picture” (Moya-Anegon et al., 2004): “a spatial representation of the relationship among […] individual papers as reflected in some formal, strictly quantifiable properties of scientific literature at a given time” (De Bellis, 2009: 142). Citations are the elements that Figure 2. Organizations by type and location 8 L. MORA ET AL. Downloaded by [Shanghai Jiaotong University] at 03:36 25 August 2017