slide 17, 13, 14, 18, 19, 20, 22, 23, 24 - stamped date JUN81N11
slide 12 - stamped date JUN81N11
slide 10,11 - stamped date JUN81N11
slide 8, 7 - stamped date JUN81N11
slide 6 - stamped date JUN81N11
slide 3, 2 - stamped date JUN18N11
slide 10 - stamped JUN81 (box ABS-011)
slide 1 - stamped date JUN81N11