[1] ARHANGEL'SKII A. V.: The frequency spectrum of a topological space and the classification of spaces. Sov. Math. Dokl. 13 (1972), 1185-1189 [Transl. from: Dokl. Akad. Nauk SSSR 206 (1972), 265-268]. MR 0394575

[2] ARHANGEL'SKII A. V.: The frequency spectrum of a topological space and the product operation. Trans. Moscow Math. Soc. 40 (1981), 164-200.

[3] DOLECKI S.-SITOU S.: Precise bounds for sequential order of product of some Fréchet topologies. Topology Appl. 20 (1997), 1-15.

[4] DOLECKI S.-SITOU S.: Ordre squentiel du produit de certaines topologies de Frechet. C. R. Acad. Sci. Paris Sér. I Math. 322 (1996), 465-470. MR 1381785

[5] FREMLIN D. H.: Sequential convergence in $C_p (X)$. Comment. Math. Univ. Carolin. 35 (1994), 371-382. MR 1286585

[6] FRIČ R.-VOJTAS P.: Diagonal conditions in sequential convergence. In: Convergence structures 1984 (Proc. Conf. on Convergence, Bechyne, 1984). Mathematical Research/Mathematische Forschung, Bd. 24, Akademie-Verlag, Berlin, 1995, pp. 77-94. MR 0835474

[7] KRATOCHVÍL P.: Multisequences and measure. In: General Topology and its Relations to Modern Analysis and Algebra IV. (Proc. Fourth Prague Topological Sympos., Prague 1976), Part B, Soc. Czech. Mathematicians and Physicists, Prague, 1997, pp. 237-244. MR 0460576

[8] KRATOCHVÍL P.: Multisequences and their structure in sequential spaces. In: Convergence structures 1984 (Proc. Conf. on Convergence, Bechyne, 1984). Mathematical Research/Mathematische Forschung Bd. 24, Akademie-Verlag, Berlin, 1995, pp. 205-216. MR 0835487

[9] MICHAEL E.: A note on closed maps and compact sets. Israel J. Math. 2 (1996), 173-176. MR 0177396

[10] MICHAEL E.: Local compactness and cartesian products of quotient maps and k-spaces. Ann. Inst. Fourier (Grenoble) 18 (1968), 281-286. MR 0244943 | Zbl 0175.19703

[11] NOGURA T.-SHIBAKOV A.: Sequential order of product of Fréchet spaces. Topology Appl. 70 (1996), 245-253. MR 1397080 | Zbl 0854.54024

[12] SITOU S.: Ordre séquentiel du produit de deux topologies de Fréchet. Ph.D Thesis, 1995.

[13] TANAKA Y.: Products of sequential spaces. Proc. Amer. Math. Soc. 54 (1976), 371-375. MR 0397665 | Zbl 0292.54025