Ripple Counter - Circuit Diagram, Timing Diagram, and Applications
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
Digital Circuits - Counters
Digital Synchronous Counter - Types, Working & Applications
How can 'D flip-flops' act as a binary counter? - Quora
Circuit Design of a 4-bit Binary Counter Using D Flip-flops - VLSIFacts