SOURCE 1:
I have read the article Personality Differences Between Depressed Melancholic and Non-Melancholic Inpatients. The authors of this study include Alex Rubina, Marco Zanasi, Camilla Robone, and Alberto Siracusano. They took part in the actual study of these patients to determine the relation between personality disorders (such as perfectionism) on both melancholic and non-melancholic patients. Given that these authors, or rather, scientists conducted the study and have degrees in neuroscience I find them highly credible on this matter. Not only do they record their findings and ideas from the study, they reference many other credible sources which only reinforce the educational and credible value of this resource.
SOURCE 2:
The second source I have come upon is Self-Oriented Perfectionism in Eating Disorders. There are many authors/researchers that were involved and include: Josefina Castro-Fornieles, Pilar Gual, Francisca Lahortiga, Araceli Gila, Vanesa Casula, Cynthia Fuhrmann, Milagros Imirizaldu, Begona Saura, Esteve Martinez, and Josep Toro. Between all of these authors they include multiple members of Departments of Psychiatry, Clinical Psychobiology, and Medical Psychology from different credible Universities. Some are even employees of Institute Clinics of Neurosciences. These people are very involved in this subject I am researching and have much experience in this field. Just like the other source, these people have also conducted their own studies and even include multiple references whom are also credible.