J Dueck: found this too
J Dueck: two pattern sketches
J Dueck: icthus
J Dueck: six unit pattern
J Dueck: double thread pattern
J Dueck: a common motif
J Dueck: outer loops
J Dueck: detail of celtic knot
J Dueck: celtic knotwork
J Dueck: knot a bit closer
J Dueck: detail of celtic knot