APA (7th ed.) Citation

British Museum & Gayangos, P. d. (1881). Catalogue of the manuscripts in the Spanish language in the British Museum. Printed by order of the Trustees [of the British Museum].

Chicago Style (17th ed.) Citation

British Museum and Pascual de Gayangos. Catalogue of the Manuscripts in the Spanish Language in the British Museum. London: Printed by order of the Trustees [of the British Museum], 1881.

MLA (9th ed.) Citation

British Museum and Pascual de Gayangos. Catalogue of the Manuscripts in the Spanish Language in the British Museum. Printed by order of the Trustees [of the British Museum], 1881.