“…These limits do not apply to sterile neutrinos (they may have only a small mixing angle with the ordinary neutrinos; Kusenko & Segré 1997; Fuller et al 2003). Papers dealing with the origin of pulsar kicks can be found in Kusenko & Segré (1999), Akhmedov, Lanza & Sciama (1997), Barkovich, D'Olivo & Montemayor (2004), Barkovich et al (2001), Burrows & Hayes (1996), Chandra, Goyal & Goswami (2002), Chugai (1984), Mosquera Cuesta (2000, 2002), Mosquera Cuesta & Fiuzza (2004), Dorofeev, Rodionov & Ternov (1984), Duncan & Thompson (1992), Elizalde, Ferrer & de la Incera (2002, 2004), Erdas & Feldman (1990), Goyal (1999), Grasso, Nunokawa & Valle (1998), Gott, Gunn & Ostriker (1970), Harrison & Tademaru (1975), Horvat (1998), Janka & Raffelt (1998), Lai & Qian (1998), Lambiase (2005a,b), Loveridge (2004), Nardi & Zuluga (2001), Qian (1997) and Voloshin (1988).…”