BOOK I
GENERAL PART
TITLE II
ON CRIME
CHAPTER III
PERPETRATORS OF CRIME
Article 29. Perpetrators
Participation in the commission of a crime may take on the form of principal authorship, instigation or complicity and there can be various joint participants in the same act.
Article 30. Authorship
1. A principal is the person who commits the act either directly or through a third party who serves as an instrument for the former.
2. Coprincipals of an act are any persons who, by expressed or tacit agreement, take direct part in commission of a crime or join forces in commission of the same crime.
EDIT.