P. Andaloro, The 3x + 1 Problem and Directed Graphs, Fibonacci Quarterly 2002, vol.40, pp.43-54

P. Andaloro, On Total Stopping Times under 3x + 1 Iteration, Fibonacci Quarterly, vol.38, issue.1, pp.73-78, 2000.

S. ¸. Andrei, M. Kudlek, and R. S. Niculescu, Some Results on the Collatz Problem, Acta Informatica, vol.37, issue.2, pp.145-160, 2000.

S. ¸. Andrei and C. Masalagiu, About the Collatz Conjecture, Acta Informatica, vol.35, issue.2, pp.167-179, 1998.

M. Chamberland, An Update on the 3x+1 Problem, Butlleti de la Societat Catalana de Matematiques, vol.18, pp.19-45, 2003.

Z. Chuanzhong, Some Discussion on the 3x+1 Problem, Journal of South China Normal University (Natural Science Edition, issue.3, 1995.

?. , ?. , and ?. ?????), , 1995.

, ?? 3 ?

I. Korec and ?. S. Znám, A Note on the 3x+1 Problem, American Mathematical Monthly, vol.94, pp.771-772, 1987.

N. Mondal and P. P. Ghosh, A General Class of Collatz Sequence and Ruin Problem, 2013.

C. Wikipedia and . Conjecture, Online: Collatz Conjecture -As an abstract machine that computes in base two