Having previously stated that Batiffol’s edition of the Syntagma doctrinae could not be found online, I must, once again, correct myself.
It is part of the second fascicle of his Studia patristica and may be found at https://archive.org/details/studiapatristica00bati. His edition of the Fides patrum, however, is not available online as far as I can determine.
ancientchurchorders 