“…In addition, hypotheses about the possible factors that motivated this decline have been identified in various studies. The formulated hypotheses are based on the analysis undertaken by various authors, such as Porter (1996), Corredor andGoñi (2011), Wood Jr (2001), Tolovi (1994), Cordeiro (2004Cordeiro ( , 2009, Wood and Caldas (1995), Campos (1989), Jesus (2000), Vasconcelos and Teixeira (1997), Asif et al (2009), Zilbovicius (1999), Pyzdek (2001), Brown (2013), Antony (2013), Mosadeghrad (2013Mosadeghrad ( , 2014, Parvadavardini et al (2015) and Zu et al (2010).…”