1. DECAYING OF THE MARBLE AND LIMESTONE MONUMENTS IN THE URBAN ENVIRONMENT. CASE STUDIES FROM SAINT PETERSBURG, RUSSIA. Authors: OLGA V. FRANK-KAMENETSKAYA, DMITRII YU. VLASOV, MARINA S. ZELENSKAYA, IRINA V. KNAUF, MARIYA A. TIMASHEVA.2. PETERSBURG STONE MONUMENTS ON THE BASIS OF COMPLEX MONITORING RESULTS. Authors: OLGA V. FRANK-KAMENETSKAYA, DMITRII YU. VLASOV.3. CALCIUM OXALATES IN BIOFILMS ON THE SURFACE OF ARCHEOLOGICAL MONUMENTS OF TAURIC CHERSONESOS (CRIMEA). Authors: MARINA S. ZELENSKAYA, IRINA V. KNAUF, OLGA V. FRANK-KAMENETSKAYA, DMITRII YU. VLASOV.