[975] Waite 1893.

[976] Lesdain 1912.

[977] Zopf 1907.

[978] Lesdain 1910.

[979] Zukal 1896, p. 258.

[980] [See p. 51.]

[981] [See p. 177 et seq.]

[982] Zahlbruckner 1903.

[983] Steiner 1896.

[984] Müller-Argau 1880.