BibSlavKon: 697 hits for 13 on page 26

The Bibliography of International Congresses of Slavists (1929-2018) was converted from thirteen printed volumes into a database in cooperation with the Slavonic Library in Prague (Slovanská knihovna Praha) and contains 8550 records. Since 2008 the Bibliography appear only in electronic form and will be updated in five-year interval according to the next Congresses of Slavists. The further information can be found here. The overview of the classification can be found: here.

Your search for Volume 13 provides 697 hits
251	Upotreblenije leksemy ta v prostranstvenno-vremennych obstojateľstvach v slovenskich dialektach Friuli : ešče raz o slavjano-romanskom kontakte Benacchio, Rosanna - Contributi italiani al XIII Congresso internazionale degli slavisti : (Ljubljana 15–21 agosto 2003) (2003), 11–23
252	Jazyk i dialekt : otnositeľno statusa rusinskich govorov v Vengrii Benedek, Gergely - Studia slavica Academiae scientiarum Hungaricae 48 (2003) 1/3, 11–24
253	Kommunikativnyje fragmenty v chudožestvennom tekste Björklund, Martina - Studia finlandensia (2003), 27–34
254	Mižslavjanskaje moŭnaje ŭzajemadzejanne : sacyjakuľturny aspekt Cychun, Henadz’ - 2003, 23 s.
255	O akcenatskom proznom ritmu u srpskom književnom jeziku : (na primjerima iz Andrićeve Proklete avlije) Dešić, Milorad - Zbornik Matice srpske za slavistiku (2003), 79–87
256	Prvý preklad celej Biblie do slovenčiny Doruľa, Ján - XIII. medzinárodný zjazd slavistov v Ľubľane : príspevky slovenských slavistov (2003), 135–139
257	The Emergence of Slavonic Post-literary Languages : some Preliminary Observations Dunn, John A. - 13th International Congress of Slavists [online] (2003), 25 s.
258	Einflüsse slavischer Sprachen auf Morphologie und Grammatik des Jiddischen Eggers, Eckhard - Die slawischen Sprachen im aktuellen Funktionieren und historischen Kontakt : Beiträge zum XIII. Internationalen Slawistenkongress vom 15. bis 21. August 2003 in Ljubljana (2003), 99–110
259	Explication in Russian-Swedish Translation : Sociolinguistic and Pragmatic Aspects Englund Dimitrova, Birgitta - Swedish Contributions to the Thirteenth International Congress of Slavists, Ljubljana, 15–21 August 2003 (2003), 21–31
260	A Pragmatic Feature of [Nonserious] and Power in Czech Fidler, Masako U. - American Contributions to the 13th International Congress of Slavists : Ljubljana, August 2003 (2003), 51–64

Bibliography of International Congresses of Slavists (BibSlavKon)