Carolina Benedetti and Nantel Bergeron, The antipode of linearized Hopf monoids, Algebr. Comb. 2 (2019), no. 5, 903–935. MR 4023571, DOI 10.5802/alco.53

J. S. Frame, G. de B. Robinson, and R. M. Thrall, The hook graphs of the symmetric groups, Canad. J. Math. 6 (1954), 316–324. MR 62127, DOI 10.4153/cjm-1954-030-1 Petter Brändén, Unimodality, log-concavity, real-rootedness and beyond, Handbook of enumerative combinatorics, Discrete Math. Appl. (Boca Raton), CRC Press, Boca Raton, FL, 2015, pp. 437–483. MR 3409348 Arthur T. Benjamin and Jennifer J. Quinn, Proofs that really count, The Dolciani Mathematical Expositions, vol.27, Mathematical Association of America, Washington, DC, 2003. The art of combinatorial proof. MR 1997773 K. Appel, W. Haken, and J. Koch, Every planar map is four colorable. II. Reducibility, Illinois J. Math. 21 (1977), no. 3, 491–567. MR 543793 Schoenberg A (1975) Composition with twelve tones. In: Schoenberg A (ed) Style and idea. Selected writings of Arnold Schoenberg. Faber & Faber, London, pp 102–143Hapke T (2012) Wilhelm Ostwald’s combinatorics as a link between in-formation and form. Libr Trends 61(2):286–303 Chen Chuan-Chong and Koh Khee-Meng, Principles and Techniques in Combinatorics is another text that approaches the subject through olympiad problems.

T. Kyle Petersen, Eulerian numbers, with a foreword by Richard Stanley, Birkhäuser Advanced Texts: Basler Lehrbücher. [Birkhäuser Advanced Texts: Basel Textbooks], Birkhäuser/Springer, New York, 2015. MR 3408615, DOI 10.1007/978-1-4939-3091-3 Rottman M (2015) Donald Judd’s arithmetics and Sol LeWitt’s combinatorics. On the relationship between visual and mathematical in New York art around 1960. In: Emmer M (ed) Imagine math 3. Between culture and mathematics. Springer, Cham Tullio Ceccherini-Silberstein, Fabio Scarabotti, and Filippo Tolli, Representation theory of the symmetric groups, CUP 2010. A slow-paced introduction to symmetric functions and representations of symmetric groups, taking a rather nonstandard approach. (Particularly recommended due to the inclusion of partition algebras, which are currently underexposed in textbooks.) A. Björner, Topological methods, Handbook of combinatorics, Vol. 1, 2, Elsevier Sci. B. V., Amsterdam, 1995, pp. 1819–1872. MR 1373690 Winter M (2019) A few more thoughts about Leibniz: the prediction of harmonic distance in harmonic space. MusMat Braz J Music Math 3:79–92Carolina Benedetti and Nantel Bergeron, The antipode of linearized Hopf monoids, Algebr. Comb. 2 (2019), no. 5, 903–935. MR 4023571, DOI 10.5802/alco.53 Richard Ehrenborg, On posets and Hopf algebras, Adv. Math. 119 (1996), no. 1, 1–25. MR 1383883, DOI 10.1006/aima.1996.0026 Miklós Bóna, Combinatorics of permutations, 2nd ed., Discrete Mathematics and its Applications (Boca Raton), CRC Press, Boca Raton, FL, 2012. With a foreword by Richard Stanley. MR 2919720, DOI 10.1201/b12210

George D. Birkhoff, A determinant formula for the number of ways of coloring a map, Ann. of Math. (2) 14 (1912/13), no. 1-4, 42–46. MR 1502436, DOI 10.2307/1967597 C. Krattenthaler, Advanced determinant calculus, The Andrews Festschrift (Maratea, 1998), Sém. Lothar. Combin. 42 (1999), Art. B42q, 67. MR 1701596 Cameron PJ (1994) Combinatorics: topics, techniques, algorithms. Cambridge University Press, Cambridge Anna de Mier, Lecture notes for "Enumerative Combinatorics", 2004. ( Alternative link via archive.org.) V. Reiner, D. Stanton, and D. White, The cyclic sieving phenomenon, J. Combin. Theory Ser. A 108 (2004), no. 1, 17–50. MR 2087303, DOI 10.1016/j.jcta.2004.04.009Jean Berstel, Aaron Lauve, Christophe Reutenauer, Franco Saliola, Combinatorics on Words: Christoffel Words and Repetitions in Words. Kenneth P. Bogart, Combinatorics Through Guided Discovery. (Specifically, the 2017 version is the most up-to-date so far.) This is a heavily introductory text, written as a collection of exercises with ample hints and motivation. (Yes, there is a version with solutions in the tar.gz source archive.) I have seen lots of people use this text in classes, so I assume it's good. Donald E. Knuth, The art of computer programming. Vol. 1, Fundamental algorithms, third edition [of MR0286317], Addison-Wesley, Reading, MA, 1997. MR 3077152 Joseph P. S. Kung, Gian-Carlo Rota, Catherine H. Yan, Combinatorics: The Rota Way, CUP 2009 is a nonstandard textbook, originating from Rota's MIT classes and reflecting his interests (many of which have never hit the combinatorial mainstream). Errata and a sample chapter. Fritz D (2008) Vladimir Bonačić: computer-generated works made within Zagreb’s new tendencies network (1961–1973). Leonardo 41(2):175–183