Donald G. McNeil, Jr., Precursor to H. I. V. Was in Monkeys for Millennia, in New York Times, 16 settembre 2010. URL consultato il 17 settembre 2010 (archiviato dall'url originale il 19 settembre 2010).
«Dr. Marx believes that the crucial event was the introduction into Africa of millions of inexpensive, mass-produced syringes in the 1950s. ... suspect that the growth of colonial cities is to blame. Before 1910, no Central African town had more than 10,000 people. But urban migration rose, increasing sexual contacts and leading to red-light districts.»