Verilog Programming By Naresh Singh Dobal: Design of Serial In - Serial Out Shift Register using D Flip Flop (Structural Modeling Style) (Verilog CODE).
4-Bit Universal Shift Register Behavioral Vs. Structural Description Behavioral Description – Behavior model of a shift register Describe the operation. - ppt download
VHDL Code for Flipflop - D,JK,SR,T
Verilog code for D Flip Flop - FPGA4student.com
Verilog coding: Verilog code for 4-Bit universal shift register: