Connect a microSD card to the ESP8266 or ESP32 using a microSD to SD adapter — Alex Lubbock
Recover Data from SD card using USB Data cable (memory card) - YouTube
DIY USB SD Card Reader for PC/Mac possible? - Project Guidance - Arduino Forum
U0909A (USB2.0 9 Pin Header to SD Card Reader)
PC-3000 Flash. Monolith pinout determination guide. Variant 1 | PC-3000 Support Blog
SD Adaptor, to use SD flash cards with Teensy, Arduino and other AVR boards
How to build a device to read SPI/SDIO input and convert to USB to read/write data onto a USB storage device from a 9-pin SD card interface? : r/embedded
Read only usb flash drive | Hardware Tweaks, hacks and modifications