Table 1.

Seeding set of papers for the backward and forward snowballing

Study	Journal	Topic	Year	$\sum$ Refs.	$\sum$ Cits.
Gaston and  O'Neill [47]	Philosophical Transactions of the Royal Society of London	Roadmap paper on automated species identification	2004	91	215
MacLeod  et al. [88]	Nature	Roadmap paper on automated species identification	2010	10	104
Cope et al. [33]	Expert Systems with Applications	Review paper on automated leaf identification	2012	113	108
Nilsback et al.  [105]	Indian Conference on Computer Vision, Graphics and Image Processing	Study paper on automated flower recognition	2008	18	375
Du et al.  [40]	Applied Mathematics and Computation	Study paper on automated leaf recognition	2007	20	215

Table notes: Number of citations based on Google Scholar, accessed June 2016