Someone queried this but, yes, that spelling is fine. At least, that is how the Latin texts do it. (Indeed, a good way to locate Latin commentaries on Ocham is to Google it like that).
'Ockham' is of course better known (as is 'Occam'). But who can say which is right. 'Ockham' is the spelling of the picturesque Surrey village where the man is supposed to come from. Yet even that is uncertain. He may have come from 'Oak Ham' or Woking, which is not picturesque at all, being one of those many old English towns that somehow got annihilated in the twentieth century when the councils improved them with monstrous brown brick shopping malls and ring roads & dreaded pedestrian precincts filled with litter and other undesirable things.