Dimitrov, V. S.; Jullien, G. A.; and Miller, W. C. "Complexity and Fast Algorithms for Multiexponentiations." IEEE Trans. Comput.49, 141-147, 2000.Finch, S. R. "Porter-Hensley Constants." §2.18 in Mathematical Constants. Cambridge, England: Cambridge University Press, pp. 156-160, 2003.Havil, J. Gamma: Exploring Euler's Constant. Princeton, NJ: Princeton University Press, p. 113, 2003.Knuth, D. E. "Evaluation of Porter's Constant." Computers Math. Appl.2, 137-139, 1976.Knuth, D. E. The Art of Computer Programming, Vol. 2: Seminumerical Algorithms, 3rd ed. Reading, MA: Addison-Wesley, 1998.Lochs, G. "Statistik der Teilnenner der zu den echten Brüchen gehörigen regelmässigen Kettenbrüche." Monatsh. f. Math.65, 27-52, 1961.Porter, J. W. "On a Theorem of Heilbronn." Mathematika22, 20-28, 1975.Sloane, N. J. A. Sequence A086237 in "The On-Line Encyclopedia of Integer Sequences."Ustinov, A. V. "The Mean Number of Steps in the Euclidean Algorithm with Odd Partial Quotients." Math. Notes88, 574-584, 2010.
![(6ln2)/(pi^2)[3ln2+4gamma-(24)/(pi^2)zeta^'(2)-2]-1/2](/images/equations/PortersConstant/Inline3.svg)
是 尤拉-馬歇羅尼常數, 
是 黎曼zeta函式, 並且 
是 格萊舍-金克林常數 (Knuth 1998, p. 357)。 符號 
通常用於表示這個常數 (Knuth 1998, p. 357, Finch 2003, pp. 156-157)，儘管其他作者使用 
(Ustinov 2010) 或 
(Dimitrov et al. 2000)。
和 
，並由下式定義
稱為 Lochs-Porter 常數，因為 Lochs (1961) 的工作。