It will not be recognized because lines are reconstructed like this:
Phys. Rev.-A21 (2011) 56
Which is not a valid format. * If there is a plot in between references, the result is sketchy at best.
Retarded author format with 2 comas Dougherty, S.M., Beasley A.J. is not recognized properly
Authors with 5 or more name particules are not recognized Joe de Rose Silva Maria
Authors with accents or weird symbols are not recognized
There is not handling for erratum-ibid
Footnotes references should not be recognized
If there is a number of a page refering to the PDF at the end of a reference, e.g. Phys.Rev. A51 (2011) 56 where 56 is the page in the PDF well it is easy to guess the parser cannot tell the difference
This is not recognized CERN-2004-003-V-1
This is not recognized either Nato Advanced Study Institutes Series: Series B, Physics, 59
When a document has multiple references sections, the result is undetermined but it definitely won't find more than one
There is no size limit for references
If numerotation or a journal is partially recognized it will end up in the misc field but it will be mangled.