Soja R. H.Dynamics of the Solar System Meteoroid Population. — University of Canterbury, 2010. — P. 158 (140). Архивировано 11 сентября 2014 года. "Comet 2P/Encke itself is not directly in the 7:2 resonance: proto-Encke, however, may have exhibited strong or weak resonant activity for at least part of its lifetime, allowing it to more easily populate the resonance with cometary dust.
Soja R. H.Dynamics of the Solar System Meteoroid Population. — University of Canterbury, 2010. — P. 158 (140). Архивировано 11 сентября 2014 года. "Comet 2P/Encke itself is not directly in the 7:2 resonance: proto-Encke, however, may have exhibited strong or weak resonant activity for at least part of its lifetime, allowing it to more easily populate the resonance with cometary dust.