A. Lages, P. Lopes,  A Proof of Euler's Theorem via Quandles, INTEGERS, vol. 22 (2022), #A44

A. Lages, P. Lopes,  P. Vojt?chovský , A Sufficient Condition for a Quandle to be Latin, J. Combin. Des., vol. 30 (2022), no. 4, 251--259

L. H. Kauffman, P. Lopes,  On the orbits associated with the Collatz conjecture, Linear Algebra Appl., vol. 615 (2021) 143 -- 154

P. Lopes,  Knot colorings,  in ``Encyclopedia of Knot Theory´´, C. Adams et al (eds.), CRC Press,   2021

L. H. Kauffman, P. Lopes,  The prevalence of persistent tangles, Topology Appl.,  vol. 271 (2020) 107040

P. Lopes,  Removing colors 2k, 2k-1, and k,  J. Knot Theory Ramifications,   vol. 28 (2019), no. 13, 1940013 (42 pages)

A. Lages, P. Lopes,  Quandles of cyclic type with several fixed points,  Electron. J. Combin.,   vol. 26 (2019) no. 3, P3.42

J. Ge, X. Jin, L. H. Kauffman, P. Lopes,  L. Zhang, Answer to a question by Nakamura, Nakanishi, and Satoh involving crossing numbers of knots, Osaka J. Math., vol. 55 (2018), no 3, 523 - 527

L. H. Kauffman, P. Lopes,  Colorings beyond Fox: the other linear Alexander quandles, Linear Algebra Appl., vol. 548 (2018), no. 1, 221 - 258

L. H. Kauffman, P. Lopes,  Infinitely many prime knots with the same Alexander invariants, J. Knot Theory Ramifications,   vol. 26 (2017), no. 9, 1743009 (13 pages)

J. Ge, X. Jin, L. H. Kauffman, P. Lopes,  L. Zhang, Minimal sufficient sets of colors and minimum number of colors, J. Knot Theory Ramifications,  vol. 26 (2017), no. 9, 1743008 (16 pages)

J. Araújo, J. P. Araújo, P. Cameron,  T. Dobson, A. Hulpke, P. Lopes, Imprimitive permutations in primitive groups, J. Algebra, vol. 486 (2017), 396--416

F. Bento, P. Lopes, The minimum number of Fox colors modulo 13 is 5, Topology Appl., vol.  216  (2017), 85--115


S. Jablan, L. Kauffman, P. Lopes, Delta diagrams, J. Knot Theory Ramifications, vol. 25  (2016), no. 9, 1641008 (19 pages)  


P. Lopes, Partial profiles of quasi-complete graphs,  J. Integer Seq., vol. 19  (2016), Article 16.2.5


S. Jablan, L. Kauffman, P. Lopes, The delunification process and minimal diagrams, Topology Appl., vol. 193  (2015), 270--289


P. Lopes, J. Matias, Minimum number of colors: the Turk's head knots case study, Discrete Math. Theoret. Computer Science, vol. 17 (2015), no. 2, 1--30 

P. Lopes, The minimization of the number of colors is different at p=11, J. Knot Theory Ramifications, vol. 24  (2015), no. 5, 1550027 (20 pages)


J. Ge, S. Jablan, L. Kauffman, P. Lopes, Equivalence classes of colorings, Banach Center Publ.,  vol. 103 (2014), 63--76


S. Jablan, L. Kauffman, P. Lopes, On the maximum number of colors for links,  J. Knot Theory Ramifications, vol.  22 (2013), no. 3,  1350013 (19 pages)


L. Kauffman, P. Lopes, The Teneva game, J. Knot Theory Ramifications, vol. 21 (2012), no. 14,  1250125 (17 pages)


P. Lopes, J. Matias, Minimum number of Fox colors for small primes, J. Knot Theory Ramifications, vol. 21 (2012), no. 3,  1250025 (12 pages)


P. Lopes, Permutations which make transitive groups primitive, Cent. Eur. J. Math. vol. 7 (2009), no. 4, 650--659


L. Kauffman, P. Lopes, Determinants of rational knots,  Discrete Math. Theoret. Computer Science, vol. 11 (2009), no. 2, 111--122


P. Lopes, Sequences of knots and their limits, in Geometry and Physics: XVI International Fall Workshop, R. L. Fernandes and R. Picken (eds.), AIP Conference Proceedings, vol. 1023, 183--186, 2008


L. Kauffman, P. Lopes, On the mininum number of colors for knots,  Adv. in Appl. Math. vol. 40 (2008), no. 1, 36--53


P. Lopes, Hyperfinite knots via the CJKLS invariant in the thermodynamic limit,  Chaos, Solitons and Fractals vol. 34 (2007), no. 5, 1450--1472


P. Lopes, D. Roseman, On finite racks and quandles,  Comm. Algebra  vol. 34 (2006), no. 1,  371--406


J. Bojarczuk, P. Lopes, Quandles at finite temperatures III, J. Knot Theory Ramifications, vol. 14 (2005), no. 3,  275--373


P. Lopes, C. Morales, The knot group and the fundamental group of the embedding 3-manifold, J. Knot Theory Ramifications vol. 14 (2005), no. 2, 265--273


F. Dionísio, P. Lopes, Quandles at finite temperatures II,  J. Knot Theory Ramifications, vol. 12 (2003), no. 8, 1041--1092


P. Lopes, Quandles at finite temperatures I,  J. Knot Theory Ramifications, vol. 12 (2003), no. 2, 159--186