embroidery stitch tutorial: the herringbone ladder stitch
CC of Suestreehouse has posted a scan of a vintage embroidery-stitch primer. If you’re just getting started or if you could use a brush-up on basic stitches, CC has got you covered!
Pumora's stich-lexicon: threaded back stitch, umschlungener Rueckstich/Rückstich (DE);
Worsted Ravelry: Masterpiece pattern by von Hinterm Stein