Bekchiev, R., Antov, M., Boyadzhiev, P., Zaemdzhikova, G., Kostova, R., Guéorguiev, B., 2022. Carabus variolosus (Fabricius, 1787) (Coleoptera: Carabidae) in Bulgaria: rediscovered after 111 years. — Historia naturalis bulgarica, 44 (10): 119—123. [PDF] doi:10.48027/hnb.44.103
Bekchiev, R., Crevecoeur, L., Gielen, K., Bosmans, B., Smets, K., Kostova, R., 2020. One Hundred Years of Solitude: Rediscovery of the Rare and Protected Beetle Rhysodes sulcatus (Fabricius, 1787) (Coleoptera: Rhysodidae) in Bulgaria. — Acta zoologica bulgarica, (in print) published online at http://www.acta-zoologica-bulgarica.eu/002372.
Kostova, R., Bekchiev, R., Beshkov, S., 2019. Coleoptera and Lepidoptera (Insecta) diversity in the central part of Sredna Gora Mountains (Bulgaria). — Bulletin of the Entomological Society of Malta, 10: 75—95. [PDF]
Bekchiev, R., Guéorguiev, B., Kostova, R., Chehlarov, E., Sivilov, O., 2018. New Records of Rare and Threatened Beetles (Insecta: Coleoptera) in Bulgaria. — Acta zoologica bulgarica, 70 (4): 501—506.
Sabella, G., Bekchiev, R., Kostova, R., 2017. Pselaphinae (Coleoptera Staphylinidae) from Sicily and Calabria (Italy). Results from a short entomological expedition in April, 2015. — 3rd International Congress 'Biodiversity, Mediterranean, Society', September 4th—6th 2015, Volume 8. Biodiversity Journal, Noto-Vendicari (Italy). 185—192 pp. [PDF]
Bekchiev, R., Sivilov, O., Kostova, R., Lapeva-Gjonova, A., 2017. Distribution of Amorphocephala coronata (Germar, 1817) (Coleoptera: Brentidae) in Bulgaria. — ZooNotes, 104: 1—3. [PDF]
Kostova, R., Lazarov, S., Bekchiev, R., Goranov, S., Simov N., Beshkov, S., 2016. Soil and cave invertebrates from the village Gintsi area. — In: Speleological Studies of Caves in Godech Municipality (Part 1), Association of Speleoclubs in Sofia, Sofia, 39—50. [PDF]
Kostova, R., Guéorguiev, B., 2016. The ground beetles (Coleoptera: Carabidae) of the Strandzha Mountain and adjacent coastal territories (Bulgaria and Turkey). — Biodiversity Data Journal, 4: e8135. doi:10.3897/BDJ.4.e8135
Kostova, R., 2015. Ground beetles (Coleoptera: Carabidae) diversity patterns in forest habitats of high conservation value, Southern Bulgaria. — Biodiversity Journal, 6 (1): 341—352.
Bekchiev, R., Brachat, V., Anlas, S., Özgen, I., Yağmur, E. A., Örgel, S., Gjonov, I., Kostova, R., 2015. Contribution to the Pselaphinae (Coleoptera: Staphylinidae) of Anatolia, Turkey. — Acta zoologica bulgarica, 67 (3): 319—324. [PDF]