Westborough – Ekaterina D. Atanasova and Nikola K. Nikolov of South Street, Westborough, are proud to announce the birth of their son, Konstantin Nikolov Nikolov, who was born March 28, 2011, at Newton-Wellesley Hospital. Konstantin's maternal grandparents are Magdalena and Dimitar Atanasovi and his paternal grandparents are Nana and Konstantin Nikolovi, all of Sofia, Bulgaria.