References

Spengel FW. 1876. Das Urogenitalsystem der Amphibien. Arb. Zool. Inst. W├╝rzburg. Apud Vitale-Calpe, R., 1969, The Fine Structure of the Organ of Bidder in the Newly Differentiate Male of Bufo arenarum. Zeit. Anat. Entwicklungsgeschl. 129 (1): 1-13.