Marchev, D., Petkova, D. Searching for short-term and long-term variabilities of the solar activity. Шумен: УИ "Еп. К. Преславски", 2003 p. 166-168,.
Marchev, D., Petkova, D. Searching for short-term and long-term variabilities of the solar activity. Шумен: УИ "Еп. К. Преславски", 2003 p. 166-168,.
Marchev, D., Petkova, D. (2003) Searching for short-term and long-term variabilities of the solar activity, Шумен: УИ "Еп. К. Преславски" p. 166-168,.
Marchev, D., & Petkova, D. (2003). Searching for short-term and long-term variabilities of the solar activity. Шумен: УИ "Еп. К. Преславски", p. 166-168.
Marchev D, Petkova D. Searching for short-term and long-term variabilities of the solar activity. Шумен: УИ "Еп. К. Преславски"; 2003. p. p. 166-168.
