Baker, M. and Norine, S. "Riemann-Roch and Abel-Jacobi Theory on a Finite Graph." Adv. Math.215, 766-788, 2007.Baker, M. and Norine, S. "Harmonic Morphisms and Hyperelliptic Graphs." Int. Math Res. Not.1, 2914-2955, 2009.Echavarria, M.; Everett, M.; Huang, R.; Jacoby, L.; Morrison, R.; Weber, B. "On the Scramble Number of Graphs." 29 Mar 2021. https://arxiv.org/abs/2103.15253.Gijswijt, D.; Smit, H.; and van der Wegen, M. "Computing Graph Gonality Is Hard." Disc. Appl. Math.287, 134-149, 2020.Harp, M.; Jackson, E.; Jensen, D.; and Speeter, N. "A New Lower Bound on Graph Gonality." 1 Jun 2020. https://arxiv.org/abs/2006.01020.Morrison, R. and Tolley, L. "Computing Higher Graph Gonality Is Hard." 6 Aug 2022. https://arxiv.org/abs/2208.03573.
of a (finite) graph 
是該圖上秩為 1 的除子的最小度數。它可以被認為是放置在該圖上的最小晶片數，這樣透過在所有可能的債務放置上的“晶片移動”可以消除 1 的債務。圖gonality 由 Baker 和 Norine (2007, 2009) 引入，類似於代數曲線上的除子理論。
是 頂點連通度, 
是 邊連通度, 
是 樹寬, 並且 
是 scramble 數 of 
(Harp et al. 2020, Echavarria et al. 2021)。