F.  Landeros, Iturriaga, T., Rodríguez, A., Vargas-Amado, G., and Guzmán-Dávalos, L., ?Advances in the phylogeny of Helvella (Fungi: Ascomycota), inferred from nuclear ribosomal LSU sequences and morphological data?, Revista Mexicana de Biodiversidad, vol. 86, pp. 856-871, 2015.

K.  Hansen, Schumacher, T., Skrede, I., Huhtinen, S., and Wang, X. - H., ?Pindara revisited ? evolution and generic limits in Helvellaceae?, Persoonia, vol. 42, pp. 186-204, 2019.

X. - C.  Wang, Liu, T. - Z., Chen, S. - L., Li, Y., and Zhuang, W. - Y., ?A four-locus phylogeny of rib-stiped cupulate species of Helvella (Helvellaceae, Pezizales) with discovery of three new species?, MycoKeys, vol. 60, pp. 45-67, 2019.

H.  Harmaja, ?Studies on cupulate species of Helvella?, Karstenia, vol. 19, no. 2, pp. 33-45, 1979.

J.  Häffner, ?Die Gattung Helvella ? Morphologie und Taxonomie?, Beihefte zur Zeitschrift für Mykologie, vol. 7, pp. 1-165, 1987.

S. P.  Abbott and Currah, R. S., ?The genus Helvella in Alberta?, Mycotaxon, vol. 33, pp. 229-250, 1988.

H.  Harmaja, ?Studies on cupulate species of Helvella?, Karstenia, vol. 19, pp. 33-45, 1979.

H.  Harmaja, ?A revision of the Helvella acetabulum group (Pezizales) in Fennoscandia?, Karstenia, vol. 17, pp. 45-58, 1977.

N. H.  Nguyen, Landeros, F., Garibay-Orijel, R., Hansen, K., and Vellinga, E. C., ?The Helvella lacunosa species complex in western North America: cryptic species, misapplied names and parasites?, Mycologia, vol. 105, pp. 1275-1286, 2013.

N.  van Vooren, ?Notes sur le genre Helvella L. (Ascomycota, Pezizales). 1. Le sous-genre Elasticae?, Bulletin trimestriel de la Fédération mycologique et botanique de Dauphiné-Savoie, vol. 199, pp. 27-60, 2010.

H.  Dissing, ?The genus Helvella in Europe, with special emphasis on the species found in Norden?, Dansk Botanisk Arkiv, vol. 25, no. 1, pp. 1-171, 1966.