Sweden has an extensive archive regarding the country’s dark past with witch trials and mass deaths.

Some really good sources are, albeit in Swedish, are listed here below.

#Literary sources

1. Emanuel Linderholm (1930) “Trolldomsprocesserna i Uppland och Uppsala 1671–1676.” In Kyrkohistorisk årsskrift.
2. Carl Gustaf Kröningssvärd (1972) Blåkulle-färderna, eller handlingar om trolldoms-väsendet i Dalarne åren 1668–1673.
3. Alf Åberg (1989) “Häxorna. De stora trolldomsprocesserna i Sverige 1668–1676.” In Esselte studium.
4. Bengt Ankarloo (1984) Trolldomsprocesserna i Sverige. Institutet för rättshistorisk forskning 1972. 2nd ed.
5. Birgitta Lagerlöf-Génétay (1990) De svenska häxprocessernas utbrottsskede 1668–1671. Bakgrund i Övre Dalarna. Social och ecklesiastik kontext. Stockholms universitet.
6. Per-Anders Östling (1998) “En tur till Blåkulla. De bortglömda sörmländska häxprocesserna 1675–1676, Sörmlandsbygden.” In Södermanlands hembygdsförbunds årsbok 1998.
7. Linda Oja (1999) Varken gud eller natur. Synen på magi i 1600- och 1700-talets Sverige. Brutus Östlings bokförlag Symposion.
8. Marie Lennersand & Linda Oja (2001) “När Djävulen vandrade genom landet. Krishantering under häxhysterin i Dalarna 1667–1671.” In Karolinska förbundets årsbok.

#Online sources

• Riksarkivet: Trolldomskommissionen (“The National Archives: The Witchcraft Commission”) It’s literally a “digital goldmine” of open access historical records when it comes to the Swedish witch hunts and trials.
• Arkiv och lärande (“Archive and Teaching”). This one‘s worth to mention since it has a great amount of intriguing texts and images, all of which with references. I’ve also taken the time to translate all chapter titles into English, which are listed here below.

1. Häxor (“Witches”; Eng. tr.)
2. Synen på trolldom (“The view on witchcraft”; Eng. tr.)
3. Lapp-Gunnil (“Lap-Gunnil”; Eng. tr.)
4. Trollskott (“Curse of sickness”; Eng. tr.)
5. Kyrkoplikt (“Church duty”; Eng. tr.)
6. Domboken (“The Book of Judgment”; Eng. tr.)
7. Rannsakning № 2 (“Examination № 2”; Eng. tr.)
8. Tolkning — Lapp-Gunnil (“Interpretation — Lap-Gunnil”; Eng. tr.)
9. Gunillas dom (Gunilla’s sentence”; Eng. tr.)
10. Karin i Krok (“Karin from Krok”; Eng. tr.)
11. Tolkning av rannsakningar — Karin i Krok (“Interpretation of examinations — Karin from Krok”; Eng. tr.)
12. Att hamna i rop och rykte (“To be accused of witchcraft”; Eng. tr.)
13. Mer om häxprocesserna (“More on the witch trials”; Eng. tr.)
14. Häxor och trolldom: Fördjupning (“Witches and witchcraft: In-depth”; Eng. tr.)

Edit: Added all the links translated into English for more direct and quick reading.

Where and when are you looking? There's an enormous literature on witchcraft in Europe, most of which will have some references to the published sources.

Levack, ed. The Witchcraft Sourcebook has examples from the ancient period to the end of the seventeenth century based in Europe and North America, which might be a good starting place for you. Ewen, ed. Witch Hunting and Witch Trials (1929) has extracts of the indictments of accused witches in the English Home Counties (Essex, Hertford, Kent, Surrey, and Sussex), along with other miscellaneous records. Notestein, A History of Witchcraft in England (1911) has a list of the pamphlet literature on witchcraft trials in England that should be available online (or through Early English Books Online). Black, Calendar of Cases of Witchcraft in Scotland gives a thorough listing of witchcraft cases in Scotland, including the majority of readily available sources. I know less about the publication of source material from the European continent.
Some other jumping off points to look for sources would be Gaskill, Witchcraft: A Very Short Introduction or the essays in Levack, ed. Oxford Handbook of Witchcraft.