Citations refer to the original publication, not to a Scieee localized version.
Guillamon Grabolosa, A., & Pantazi, C. (2007). Phase portraits of separable Hamiltonian systems. https://idus.us.es/items/cb451d0b-c80f-4f60-868f-3006102d95d5
Guillamon Grabolosa, Antoni, and Chara Pantazi. Phase portraits of separable Hamiltonian systems. 2007. https://idus.us.es/items/cb451d0b-c80f-4f60-868f-3006102d95d5.
Guillamon Grabolosa, Antoni, and Chara Pantazi. Phase portraits of separable Hamiltonian systems. 2007. https://idus.us.es/items/cb451d0b-c80f-4f60-868f-3006102d95d5.
Guillamon Grabolosa, A. and Pantazi, C. (2007) Phase portraits of separable Hamiltonian systems. Available at: https://idus.us.es/items/cb451d0b-c80f-4f60-868f-3006102d95d5.
A. Guillamon Grabolosa and C. Pantazi, “Phase portraits of separable Hamiltonian systems,” 2007. [Online]. Available: https://idus.us.es/items/cb451d0b-c80f-4f60-868f-3006102d95d5
@misc{guillamongrabolosa2007phase,
author = {Guillamon Grabolosa, Antoni and Pantazi, Chara},
title = {Phase portraits of separable Hamiltonian systems},
year = {2007},
url = {https://idus.us.es/items/cb451d0b-c80f-4f60-868f-3006102d95d5}
}
The source metadata has no journal, volume or pages. Add them from the original publication if your citation needs them.