The genealogical research in Spain must be taken through the study of different documents, among them:
Birth, marriage and death certificates.
Baptism, marriage and last rites registration certificates.
Law suits, judicial processes and sentences.
Transaction deeds, buying and selling title deed.
Partitions and the division of wealth, renting and leasing, donations.
Documentation concerning "Mayorazgos", Benefits and the Seizure of Possessions.
Nominations, Titles related to Positions, Dignities and Honorific Posts.
Grants and Powers.
Letters on the Creation and Succession of Titled Nobility.
Bulla Seals, Matrimonial Capitulations.
Accounts, Business Dealings, Powers, Requisitions.
Certificates on the concession of Coats of Arms.
Pleads and Executory of "Nobility and Bloodline Purity".
Letters and Private Correspondence.
Articles in different publications.