630
‘Tackling the Flying Toilets of Kibera’, Al Jazeera, 22 January 2013; Cyrus Kinyungu ‘Kibera’s Flying Toilets Flushed Out by PeePoo Bags’ .
631
.
632
‘World Toilet Day: Kibera Slum Hopes to Ground “Flying Toilets”’, .
633
.
634
G. R. K. Reddy, Smart and Human: Building Cities of Wisdom (HarperCollins Publishers India, 2015).
635
Halliday, Smart and Human: Building Cities of Wisdom (HarperCollins Publishers India, 2015).
636
William N. Goetzmann, Money Changes Everything: How Finance Made Civilization Possible (Woodstock: Princeton University Press, 2016), chapter 9.
637
William N. Goetzmann and K. Geert Rouwenhorst, The Origins of Value (Oxford: Oxford University Press, 2005), р. 67. См. также Glyn Davies, History of Money: From Ancient Times to the Present Day (Cardiff: University of Wales Press, 2010), рр. 180–183.
