SAVICKIS AND OTHERS v. LATVIA JUDGMENT decisions and practice and in the literature to cover all the possibilities. The reference to an “obligation” is limited to an obligation under international law, a matter further clarified in article 3.” C. International agreements on social security concluded by Latvia 79. Mutual recognition of periods of employment to be taken into account in calculating State pensions is provided for in the cooperation agreements on social security which Latvia has concluded with Lithuania (in force since 31 January 1996), Estonia (in force since 29 January 1997), Ukraine (in force since 11 June 1999), Finland (in force since 1 June 2000) and Canada (in force since 1 November 2006). A similar agreement with the Netherlands (in force since 1 June 2005) prohibits any discrimination on the ground of place of residence. Since the delivery of the Court’s judgment in Andrejeva, cited above, further bilateral agreements have been concluded, most importantly with Belarus (in force since 28 September 2010) and with Russia (in force since 19 January 2011). 80. In particular, Article 3(1) of the cooperation agreement on social security between Latvia and the Russian Federation expressly extends its scope to “permanently resident non-citizens” of Latvia. Article 10(1) provides that, in calculating a retirement pension, each of the parties is to take into account the aggregate period of employment of the person concerned in both countries. Article 4(2) provides for an exception to the effect that the principle of equality between nationals and residents of both States does not apply to the specific arrangements for the calculation of Latvian citizens’ periods of employment prior to 1991. 81. Article 25 of the agreement shares the financial burden of retirement pensions between the two States where the person concerned has become entitled to such a pension after the agreement’s entry into force. The pension in respect of employment prior to 1 January 1991 is paid by the State in which the beneficiary is resident at the time of claiming the pension. However, in respect of the period after that date, each Contracting Party has undertaken to cover the periods of employment in its own territory. Article 26 states that a pension that had already been granted before the entry into force of the agreement may also be recalculated on that basis at the express request of the beneficiary; however, any such review can only take effect from the entry into force of the agreement. 82. The agreement with Belarus contains similar provisions. 27