These two poems have very specific sources:

Number 96 refers to an installation by Eduardo Kac, Rara Avis, http://www.ekac.org/raraavis.html.

Number 83 maps the seven interrogatives—when, where, which, how, what, who, why—onto the seven elementary catastrophes of René Thom's catastrophe theory, or theory of discontinuous (abrupt) change. Anthony Judge's website, http://www.laetusinpraesens.org/musings/catastro.php, suggested the fertility of this idea to me.