I have encountered two terms recently: grammaticalization and grammaticisation. While in most papers I have read so far both terms seem to be used interchangeably, the following paper appears to differentiate between them: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3250214/
Hence, my question: What difference, if any, is there between the two terms?
Many thanks for any suggestions, references or just comments.
P.
EDIT:
Thanks to @Gaston Ümlaut's comment, my current understanding of the term gramaticization as used in the paper is that it is restricted to the result rather than the process, and, perhaps, that it only refers rather narrowly to a lexeme → grammatical formative kind of development, and not, say, the pragmatic → syntactic type of change/result. Is this correct? And have others distinguished the two terms in any way?