Solutions to the non-autonomous ABS lattice equations: Casoratians and   bilinearization
  In the paper non-autonomous H1, H2, H3$_\delta$ and Q1$_\delta$ equations in the ABS list are bilinearized. Their solutions are derived in Casoratian form. We also list out some Casoratian shift formulae which are used to verify Casoratian solutions. 
Ying Shi, Da-jun Zhang and Song-lin Zhao
nlin.SI math-ph math.MP