“…The characteristics of the 53 studies included are shown in Table 1: - Thirty-nine studies were conducted in Asia (Abhishek et al, 2015; Acharya et al, 2014; Akbolat, 2011; Aksakal et al, 2010; Alimohammadi et al, 2018; Arab et al, 2008; Bansal et al, 2013; Basu et al, 2012; Bdour, 2015; Bhagawati et al, 2015; Bhayana et al, 2016; Biglari, 2016; Danchaivijitr, 2005; Gupta et al, 2014; Haralur et al, 2015; Hiremath et al, 2016; Jabbari et al, 2012; Kumar et al, 2018; Kumar et al, 2013, 2016; S. Kumar and Rahman, 2017; Mangala Gowri, 2014; Megha and Daksha, 2013; Mirza et al, 2016; Mousavi et al, 2016; Mumtaz et al, 2010; Nandwani, 2010; Narang et al, 2012; Pagkatipunan, 2014; Reddy and Al Shammari, 2017; Reshmi et al, 2011; Riswana, 2016; Sarker et al, 2014; Sharma et al, 2013; Shivalli and Sanklapur, 2014; Singh et al, 2012; Sood and Sood, 2011; Srivastava and Bansal, 2013; Tabash et al, 2016);
- Ten in Africa (Akulume and Kiwanuka, 2016; Anozie et al, 2017; Augustin et al, 2016; El-Gilany et al, 2017; Enwere and Diwe, 2014; Hakim et al, 2014; Makhura et al, 2016; Manyele and Anicetus, 2006; Mochungong et al, 2010; Mostafa et al, 2009);
- Two in Europe (
…”