4 bits Synchronous Counter with J K Flip Flop - YouSpice
Design steps of 4-bit asynchronous up counter using J-K flip-flop
Synchronous counter
Synchronous 4-Bit counter circuit using JK-flip-flops | TikZ example
The 4-bit series binary counter using JK-flip-flops. | Download Scientific Diagram
How to design a synchronous counter 4 bit using JK flip flop that can count up even numbers from 0 to 14, and count down odd numbers from 15 to 0 in 1 system - Quora
verilog - Synchronous Counter using JK flip-flop not behaves as expected - Stack Overflow