Table 2 Distribution of references

Quantitative

Pe

Iacob and Jonkers (2006)

Op

Armistead et al. (1999) and Davenport and Short (1990)

Ioc

Akkary and Driscoll (1998), Donoso (2009), Menascé and Bennani (2006) and Di Penta et al. (2010)

CP

Donoso (2009), Schmidt (2006) and Somasundaram and Shrivastava (2009)

Cos

Quartel et al. (2010)

Av

Florez et al. (2014) and Schmidt (2006)

TO

Berander et al. (2005)

HR

Armistead et al. (1999) and Davenport and Short (1990)

Functional

IoC

Sunkle et al. (2013)

Al

The Open Group (2012)

Coh

The Open Group (2012)

Cor

Donoso (2009), Florez et al. (2014), Guadamuz (2001), Lam (2002), Schmidt (2006) and The Open Group (2012)

Con

Angelov et al. (2009) and Gómez et al. (2014)

Ga

The Open Group (2011)

GS

Bollobás (1982) and The Open Group (2012)

Cou

The Open Group (2012)

Pr

Angelov et al. (2009) and Kofman et al. (2009)

HR

Fischer et al. (2007)