Constitution http://www.constitution.ru/en/10003000-01.htm

Article 84

ThePresident of the Russian Federation shall:

[…]

c)announce a referendum according to the rules fixed by the federalconstitutional law; […]

Federal law “On Basic Guarantees of ElectoralRights and the Right of Citizens of the Russian Federation to Participate in aReferendum” (as amended onSeptember 27, December 24, 2002; June 23, July 4, 2003)

http://www.legislationline.org/documents/id/4170 

Article 14. Initiative to Hold aReferendum

1. Citizens of the Russian Federation eligible to participate in areferendum may put forward an initiative to hold a referendum in the RussianFederation. Federal constitutional laws, federal laws, laws of Subjects of theRussian Federation may delegate the right to initiate a referendum to othersubjects.

4. A referendum of asubject of the Russian Federation shall be called by the legislative(representative) body of state power of the subject of the Russian Federationin accordance with this Federal Law, other federal laws, the constitution(charter) or law of the subject of the Russian Federation.

FederalConstitutional Law of the Russian Federation “About the Referendum of the Russian Federation”

(as of April 24, 2008)

http://cis-legislation.com/document.fwx?rgn=6629

Назначение референдума

Статья 14. Инициатива проведения референдума

1. Инициатива проведения референдума принадлежит:

1) не менее чем двум миллионам граждан РоссийскойФедерации, имеющих право на участие в референдуме, - при условии, что натерритории одного субъекта Российской Федерации или в совокупности за пределамитерритории Российской Федерации находится место жительства не более 50 тысяч изних;

2) Конституционному Собранию - в случае, предусмотренномчастью 3 статьи 135 Конституции Российской Федерации;