“…Many reasons to encourage co-authorship in research works have been cited in the literature, one of the most recurrent is that unlike publishing individually, the co-authorship has a greater impact on the research in terms of the number of publications and citation (Lee and Bozeman, 2005;Ponomariov and Boardman 2010). Which is why, over time, coauthorships in all disciplines have increased (Lopaciuk 2016;De Stefano et al, 2013;Kronegger et al, 2011;Acedo et al, 2006;Laband and Tollison, 2000), and the number of coauthors per publication has also increased (Goyal et al, 2006;Wuchty et al, 2007) although the degrees and types of collaboration differ from one country to another, and from discipline to discipline. For example, Newman (2001Newman ( , 2004a when analyzing three collaborative scientific networks: Physics, Mathematics and Biology, found that theoretical investigations have, on average, fewer authors (1.99-2.22) than those from experimental areas (2.66-3.75),…”