Recommendations to unify phenological observations in Russia oleh Alexander A. Minin, Alexander A. Ananin, Yuri A. Buyvolov, Evgeniy G. Larin, Pavel A. Lebedev, Natalia V. Polikarpova, Irina V. Prokosheva, Marina I. Rudenko, Inna I. Sapelnikova, Violetta G. Fedotova, Elena A. Shuyskaya, Marina V. Yakovleva, Oksana V. Yantser