"including perhaps" is correct and usable in written English.
It is typically used when suggesting a possibility. For example, "I am not sure what caused the problem, including perhaps a faulty circuit."
Many voters seemed to agree, including, perhaps, some novelists.
But the majority, including perhaps most of the protesters, haven't.
But progress -- including, perhaps, progress in safety -- has bypassed both.
But Alabama forced five turnovers, including perhaps the game's biggest play.
James looked as if he wanted to be just about anywhere else, including perhaps Guant?mo.
Its population is now around 12m, including perhaps 6m migrant workers.
Inevitably, there will be more development, including, perhaps, high-rise condos.
CNN scrapped its scheduled programs, including, perhaps mercifully, "Parker Spitzer" to focus on the rescue.
They are prime hunting grounds for refugee members of al-Qaeda, including, perhaps, Osama bin Laden.
Hormones, including perhaps juvenile hormone, may be agents for the control of such changes.
There are other copies, including, perhaps, at the paper's offices in New York.
