A bottom-up practitioner-derived set of Essential Variables for Protected Area management oleh Herman Hummel, Valerie Kalle, Louise Bienfait, Yolande Boyer, Marco Heurich, Juraj Svajda, Mihai Adamescu, Constantin Cazacu, Félix Manuel Medina, Rasa Morkūnė, Arturas Razinkovas-Baziukas, Dimitris Poursanidis, Orhideja Tasevska, Ajman Al Malla, Ana Stritih, Christian Rossi, Salvador Arenas-Castro, Claudia Carvalho-Santos, Izak P.J. Smit, Emiliana Valentini, Alessandra Nguyen Xuan, Daniel Orenstein, Antonello Provenzale, Rutger de Wit, Christiaan Hummel