for those who don't find a sd card socket for the core stm32F4.
you could use micro SD card and the ADAPTATOR will be the socket like:http://www.ucapps.de/mbhp_sdcard.html
first solder unused component legs to the adaptator:
solder to the core but leave some space to the board for avoid short (be carefull pinning):
you could fix it (glue) if you want (not done for me legs are sufficiant) et voila!