82 - 86 • travel documents (including expired ones); • documents regarding applications to acquire nationality or obtain proof of nationality; • certificate of naturalization; • certificate of renunciation of nationality; • previous responses by States to enquiries on the nationality of the applicant; • marriage certificate; • military service record/discharge certificate; • school certificates; • medical certificates/records (e.g. attestations issued from hospital on birth, vaccination booklets); PART TWO • identity and travel documents of parents, spouse and children; • immigration documents, such as residence permits of country(ies) of habitual residence; • other documents pertaining to countries of residence (for example, employment documents, property deeds, tenancy agreements, school records, baptismal certificates); and • record of sworn oral testimony of neighbours and community members. 85. Information concerning the circumstances in the country or countries under consideration covers evidence about the nationality and other relevant laws, their implementation and practices of relevant States, as well as the general legal environment in those jurisdictions in terms of respect by the executive branch for judicial decisions. It can be obtained from a variety of sources, governmental and non-governmental. The complexity of nationality law and practice in a particular State may justify recourse to expert evidence in some cases. 86. For such country-related information to be treated as accurate, it needs to be obtained from reliable and unbiased sources, preferably more than one. Thus, information sourced from State bodies directly involved in nationality mechanisms in the relevant State, or non-State actors which have built up expertise in monitoring or reviewing such matters, is preferred. It is important that country-related information is continuously updated so that changes in nationality law and practice in relevant countries are taken into account. That being said, the country-related information relied on should be contemporaneous with the nationality events that are under consideration in the case in question. In addition, where the practice of officials involved in applying the nationality laws of a State appears to differ by region, this must be taken into account with respect to the country-related evidence relied on. 33