Table 1. Scheme used to classify the individual authors of a publication.

Author category	Explanation
NS*	Authors with a clear background in and focus on NS or engineering
SS**	Authors with a clear background in and focus on SS (see definition in Section 1.2.1)
Multidisciplinary	Authors educated or with backgrounds in/foci on both NS and SS
Unclear	No disciplinary background identifiable, particularly, young authors and authors from outside the academia with few publications and little information published on the web

* NS: natural scientist

** SS: social scientist.