Три добруджански рода (Three families of the Dobrouja)Gospodin Velikov, Lyubomir Penev · First published 2016Open the Tome
Scaling in Ecology and Biodiversity ConservationKlaus Henle, Simon Potts, William Kunin, Yiannis Matsinos, Jukka Simila, John Pantis, Vesna Grobelnik, Lyubomir Penev, Josef Settele · First published 2014Open the Tome
Atlas of Biodiversity RiskJosef Settele, Lyubomir Penev, Teodor Georgiev, Ralf Grabaum, Vesna Grobelnik · First published 2010Open the Tome
