La inmutabilidad divina en el contexto de la idea de Dios de la Patrística incipiente / Ana Carrasco Romero. (OCLC #52599176)

RDA 7.9.1.3 details which elements should be recorded when cataloging a dissertation or thesis (degree, institution, year) but does not specify MARC fields or punctuation.

The LC-PCC PS for that rule gives a preference for recording these elements in separate subfields of 502, with no surrounding punctuation:

502 __ ǂb Ph. D. ǂc University of Toronto ǂd 1974

It also says not to routinely convert such notes from AACR2-style, so I left this one as is when upgrading the record:

502 __ ǂa Thesis (doctoral)--Pontificia universitas sanctae crucis,
  1995.