GeoReM is a Max Planck Institute database for reference materials of geological and environmental interest, such as rock powders, synthetic and natural glasses as well as mineral, isotopic, biological, river water and seawater reference materials. It contains published analytical data and compilation values (major and trace element concentrations and mass fractions, radiogenic and stable isotope ratios). GeoReM covers all important metadata about the analytical values such as uncertainty, analytical method and laboratory. Sample information and references are also included. GeoReM contains almost 3,400 reference materials, about 46,200 analyses from almost 10,000 papers, and preferred analytical values (State: November 2017).

The database GEOROC is maintained by the Geoscience Centre at Göttingen University. The database is a comprehensive collection of published analyses of volcanic rocks and mantle xenoliths. It contains major and trace element concentrations, radiogenic and nonradiogenic isotope ratios as well as analytical ages for whole rocks, glasses, minerals and inclusions. Samples come from 11 different geological settings. Metadata include, among others, geographic location with latitude and longitude, rock class and rock type, alteration grade, analytical method, laboratory, reference materials and references.

The OSF Preprints search combines records from various preprint repositories, including arXiv, bioRxiv, Cogprints, PeerJ, PsyArXiv, RePEc and SocArXiv.

zbMATH Open (formerly known as Zentralblatt MATH) is the world's most complete and longest running abstracting and reviewing service in pure and applied mathematics. The MATH Database contains several million entries drawn from more than 3,500 serials and journals, and more than 1,100 book series and monographs. The entries are classified according to the Mathematics Subject Classification Scheme (MSC 2000).