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2. Behavior of piglets during castration with and without local anesthesia;T Horn;Dtsch Tierarztl Wochenschr,1999
3. Local and general anesthetic effects on behavior and performance of two- and seven-week-old castrated and uncastrated piglets;JJ McGlone;J Anim Sci,1988
4. IASP Task Force on Taxonomy, edited by H. Merskey and N. Bogduk. PART III: Pain Terms, A Current List with Definitions and Notes on Usage. Classification of Chronic Pain. ©1994; 209–214, updated 2011.
5. Tierschutzgesetz in der Fassung der Bekanntmachung vom 18. Mai 2006 (BGBl. I S. 1206, 1313), das zuletzt durch Artikel 101 des Gesetzes vom 20. November 2019 (BGBl. I S. 1626) geändert worden ist.