A manual for writers of research papers, theses, and dissertations, 7th edition - Kate L. Turabian 2007

Journal title
Parenthetical citations–reference list style: citing specific types of sources
Part II. Source Citation

After the article title, list the journal title in italics, with headline-style capitalization (see 22.3.1). Give the title exactly as it appears on the title page or above the table of contents of the journal; do not use abbreviations, although you can omit an initial The (Journal of Business). If the official title is an initialism such as PMLA, do not expand it. For foreign-language journals, you may use either headline-style or sentence-style capitalization, but retain all initial articles (Der Spiegel).