Kohll and Decker (1998); Ferlini (2000); Geraets-Smits and Peerbooms (2001); Vanbraekel (2001); Inizan (2003); Müller Fauré and Van Riet (2003); Leichtle (2004); Watts (2006); Stamatelaki (2007); Elchinov (2010).
Kohll ja Decker (1998); Ferlini (2000); Geraets-Smits ja Peerbooms (2001); Vanbraekel (2001); Inizan (2003); Müller Fauré ja Van Riet (2003); Leichtle (2004); Watts (2006); Stamatelaki (2007); Elchinov (2010).