The plural, the possessive case of a noun, is formed by adding an apostrophe to the plural form of the noun. With a few exceptions, the possessive of personal pronouns is not formed by adding an apostrophe. My, mine, your, yours, his, her, hers, its, our, ours, your, yours, their, theirs, whose. Pronouns as Object. They gave the award to her and me.
Abbreviations are acceptable.
When trying to decide whether to use a or an before an abbreviation, choose the article based on how the abbreviation is pronounced.