Periods after abbreviations

[Kim & Rima McKinzey]

>...Not true--i was explicitly taught (in the US), and have seen in usage
>manuals, that the commas in such circumstances are optional, and it doesn't
>matter which you use as long as you're consistent (though the Chicago Manual
>prefers inclusion of the comma, with the stated reason being to avoid the
>risk of ambiguity).

I remember being taught to put in a comma before the "and."  This is
clearly demonstrated in the wonderful quote:

"I dedicate this book to my parents, Ayn Rand and God."

Rima