Complex Economic Activities Concentrate in Large Cities. - Pierre-Alexandre Balland; Cristian Jara-Figueroa; Sergio Petralia; Mathieu P. A. Steijn; David Rigby; César A. Hidalgo 001 (CoRR, 2018)

Improvement on the association strength: Implementing a probabilistic measure based on combinations without repetition. - Mathieu P. A. Steijn (Quant. Sci. Stud., 2021)