I have a copy of the '79, maybe the '76 in my archives.
Are you loooking for V= ZIKCSW and it's linked equations?
K in Table 23-I (0.67 thru 2.5 depending on structure)
CS <= .14
C = 1/(15 * sqrt T)
T = .05 Hn / sqrt D
Z = zone factor
Zone 1 = 3/16
Zone 2 = 3/8
Zone 3 = .75
Zone 1 = 1.0
D = structure dimension in direction of applied force
I = Importance factor (1.0, 1.25 & 1.5)
S = 1.5 default value