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

Names and titles - Personal names
Abbreviations
Part III. Style 20 spelling

In general, do not abbreviate a person's first (Benj. Franklin) or last name. Once you have used a full name in text, use just the person's last name in subsequent references. However, if you are referring to more than one person with that last name, spell out their names fully on each use to avoid confusion (Alice James, William James). If you refer to these names very frequently in your paper, you may instead use abbreviations that you devise (AJ, WJ), but be sure to treat these abbreviations as described in 24.1.2.

Some individuals are known primarily by initials in place of a first and/ or middle name. Such initials should be followed by a period and a space. If you abbreviate an entire name, however, omit periods and spaces.

G. K. Chesterton

but

JFK

M. F. K. Fisher

but

FDR

Social titles such as Ms. and Mr. should always be abbreviated and capitalized, followed by a period. In most papers, however, you need not use such titles unless there is a possibility of confusion, such as referring to either a husband or wife.

Write abbreviations such as Sr., Jr., III (or 3rd), and IV (or 4th) without commas before them. Use them only after a full name, not with a surname alone, although royal and religious figures may be known only by a first name. Do not spell out the term when it is part of a name (for example, not John Smith Junior).

Oliver Wendell Holmes Jr.

William J. Kaufmann III

Mary II