Finding concordat texts

Online concordat collections in the original languages

Concordats of many countries

• Concordat course material, Pontifical Gregorian University, (March 2013)
     —  concordats presently in force listed by country
     —  concordats listed by continent
     —  number of concordats
     —  world map of concordat states
     —  collections (racolte) of concordats
     —  and much more
• The concordats of John Paul II, (October 1978 to April 2005) Most concordats are in Italian, with a sprinkling of French, Spanish and Portuguese and English. There are 98 concordats here, arranged according to country, from Albania to Venezuela. (Click on the tab for i concordati.)
• Concordats and Agreements of the Holy See (1929-1996) This collection on the Vatican site contains 59 concordats in reverse chonological order. Here, too, most texts are Italian, with a few in French, Spanish and Portugese and English. (The Vatican retitled the page in 2014 to drop the word "concordats", which still survived in the Italian original.)
• A few others are tucked away elsewhere on in the Vatican site, where you can search for the word for concordat in the sections for various languages. The terms to enter, (in the order listed on the Vatican webpage) are Deutsch — Konkordat, English — concordat, Español — concordato, Français — concordat, Italiano — concordato, Portugês — concordata.
• The Church Law Society in the Czech Republic. Large collection of concordats (and related documents) in many languages.
• Church-state legislation in the European Union has been posted by the University of Rome's Faculty of Law. The index is by country and concordats are scattered among other church-state legislation of each nation. 
• United Nations Treaty Series Online Collection. All treaties entered into by any UN member since 24 October 1945 are published by the UN, some of them online. Under "participant search" tick "Holy See". This yields a couple of dozen bilateral treaties, i.e., concordats.

Individual countries

• Religious freedom legislation for various countries, as well as international agreements, but only a couple of concordats. International Center for Law and Religious Studies, Brigham Young University
• Germany: Rechtsquellen zum deutschen Staatskirchenrecht (Legal sources of German state-church jurisprudence). Good private collection of concordat texts in German.
• Germany: Konkordatsurteil by the EKD, the German Lutheran Church. Court judgements on how concordats are to be integrated into German law. All texts in German.
• Spain: Acuerdos con Santa Sede (Accords with the Holy See) A search here for "concordato" yields five concordat texts in Spanish. Excerpts of four concordats are translated into English by the Spanish Ministry of Justice.

Printed concordat collections in the original languages

• 1950 – 1999
  There is a collection of concordat texts by José Tomás Martín de Agar y Valverde, Raccolta di concordati (1950-1999), which is the index from his book of the same name published in the Vatican City in 2000 (ISBN: 9788820927585) It lists concordats with 35 countries.
• 1801 – 2002
  There is also one called Enchiridion dei Concordati. Due secoli di storia dei rapporti Chiesa-Stato from Napoleon to the (still unratified) Czech concordat of July 2002. According to a review, "The compendium, published by the Publisher Dehoninana of Bologna, offers all the Holy See's agreements with the States in the last two centuries. The concordats are presented in the languages they were written in before translation into Italian. The alterations in the concordat texts are also included. For example, the Spanish texts appear between 18 concordats, protocols, conventions, agreements or exchanges of notes."
• 1895 –
  More recent concordats can be hard to track, unless you have access to the Acta Apostolica Sedis which publishes official Church documents and legislation about twelve times a year.  It was begun in 1895, under the title of Acta Sanctae Sedis.
• Code européen: droit et religion. U. E. les pays de la Méditerranée (2001), edited by Prof. Berlingò, contains French translations of concordats with the Mediterranean countries (Spain, France, Italy and Portugal) which have been dealt with in the first volume. http://www.churchstate.eu/Publications/Code-europ-en/1,000000274931,8,1