Gritsai، Olga؛ van der Wusten، Herman (2000). "Moscow and St. Petersburg, a sequence of capitals, a tale of two cities". GeoJournal. ج. 51 ع. 1/2: 33–45. DOI:10.1023/A:1010849220006. JSTOR:41147495. S2CID:154264277.
Gritsai، Olga؛ van der Wusten، Herman (2000). "Moscow and St. Petersburg, a sequence of capitals, a tale of two cities". GeoJournal. ج. 51 ع. 1/2: 33–45. DOI:10.1023/A:1010849220006. JSTOR:41147495. S2CID:154264277.
Gritsai، Olga؛ van der Wusten، Herman (2000). "Moscow and St. Petersburg, a sequence of capitals, a tale of two cities". GeoJournal. ج. 51 ع. 1/2: 33–45. DOI:10.1023/A:1010849220006. JSTOR:41147495. S2CID:154264277.