Later in the DATA step, when you want to process the variables in the array, you can refer to a variable by either its name or its array reference. For example, the names Reference and books{1} are ...

CATALOG DESCRIPTION: discrete-time random process, second-order statistics, autoregressive and moving average processes, linear prediction, Wiener filter, stochastic gradient (Least Mean Square) ...

You can use these variable list names to reference variables that have been previously defined in the same DATA step. The _CHARACTER_ variable lists character values only. The _NUMERIC_ variable lists ...