publications - How to Cite With Inconsistent Use of Initials

There is a paper I want to cite where, on the title page of the article, the authors names appear without any middle initials (i.e., one of the authors is Mark Smith). However, this one author frequently publishes using his middle initials (i.e., Mark E. Smith). What is the appropriate way to cite this-with the name as it appears in the article, or the name as the author typically uses it? For what it's worth, the source article appear in a mathematical journal, and I want to cite it in a paper that will eventually appear in a mathematical journal.