APA (7th ed.) Citation

Rumchev, K., Kostova, S., Popova, S., & Antova, T. (2015). Air quality and respiratory health - comparison between two cities.

Chicago Style (17th ed.) Citation

Rumchev, Krassi, S. Kostova, S. Popova, and T. Antova. Air Quality and Respiratory Health - Comparison Between Two Cities. 2015.

MLA (9th ed.) Citation

Rumchev, Krassi, et al. Air Quality and Respiratory Health - Comparison Between Two Cities. 2015.