@article {Zuffardi-Comerci1921,
	title = {Coelenterati del neo-Cretacico della Tripolitania},
	journal = {Memorie Descrittive della Carta Geologica d{\textquoteright}Italia},
	volume = {8},
	year = {1921},
	pages = {1{\textendash}23, pl. 1{\textendash}3},
	keywords = {RCBS, TIP},
	author = {Zuffardi-Comerci, R}
}
@article {Vidal1921,
	title = {Contribuci{\'o}n a la paleontologia del cret{\'a}cico de Catalu{\~n}a},
	journal = {Memorias de la Real Academia de Ciencias y Artes de Barcelona},
	volume = {17},
	year = {1921},
	pages = {89{\textendash}107},
	keywords = {RCBS, TIP},
	author = {Vidal, L M}
}
@article {VanderHorst1921,
	title = {The Madreporaria of the Siboga Expedition. Part II. Fungida},
	journal = {Siboga-Expeditie},
	volume = {16b},
	year = {1921},
	pages = {53{\textendash}98},
	keywords = {SDC, TIP},
	author = {van der Horst, C J}
}
@article {Prever1921,
	title = {I coralli Oligocenici di Sassello nell{\textquoteright}Appenino Ligure. Parte I. Corallari a calici confluenti},
	journal = {Palaeontographia Italica},
	volume = {27},
	year = {1921},
	pages = {53{\textendash}100},
	keywords = {RCBS, TIP},
	url = {http://sdrv.ms/Tcfgc6},
	author = {Prever, P L}
}
@article {Gerth1921,
	title = {Anthozoa},
	journal = {Sammlungen des Geologischen Reichs-Museums in Leiden},
	volume = {1},
	year = {1921},
	pages = {387{\textendash}445, pl. 55{\textendash}57},
	url = {http://sdrv.ms/OIdb5h},
	author = {Gerth, Heinrich}
}
@article {Fritzsche1921,
	title = {Neue Kreidefaunen aus S{\"u}damerika (Vorl{\"a}ufige Mitteilung)},
	journal = {Centralblatt f{\"u}r Mineralogie, Geologie und Pal{\"a}ontologie},
	volume = {1921},
	year = {1921},
	pages = {272{\textendash}277},
	keywords = {RCBS, TIP},
	url = {http://hdl.handle.net/2027/mdp.39015070545572},
	author = {Fritzsche, C H}
}
