Reference
Anselm Kratochwil, Angelika (Schwabe) Schwabe-Kratochwil, Erwin Scheuchl (2014): Andrena (Suandrena) portosanctana COCKERELL, 1922 and A.
(Suandrena) maderensis COCKERELL, 1922 - new taxonomical and
ecological data for two closely related endemic bee species of the
Madeira Archipelago, Portugal – Linzer biologische Beiträge – 0046_2: 1535 - 1567.