I'm unable to find anything online. Someone just said it and I thought it sounded strange (even though I've heard it a billion times in my life).
It's like it's treating "Other words" as a compound noun. I'm not a grammarian so I'm just guessing. But "other words would be..." makes sense to me, and "in alternate words" makes sense to me, but you wouldn't use other adjectives like "in further words".
Instead of saying "another approach is," you wouldn't say "in other approaches"
Hard to explain, but it just seems like a strange phrase.
The comma after words needs to be complemented by one before in because in other words is an integral phrase interrupting the rest of the sentence.
Use a semicolon to join two independent clauses when the second clause begins with a conjunctive adverb (however, therefore, moreover, furthermore, thus, meanwhile, nonetheless, otherwise) or a transition (in fact, for example, that is, for instance, in addition, in other words, on the other hand, even so).
Terrorism in the United States has become a recent concern; in fact, the concern for America's safety has led to an awareness of global terrorism.
http://owl.english.purdue.edu/owl/resource/566/01/ Retrieved on Mar 11, 2013. 11:02 am