Growth of values of binary quadratic forms and Conway rivers

This is the peer reviewed version of the following article: SPALDING, K. and VESELOV, A.P., 2018. Growth of values of binary quadratic forms and Conway rivers. Bulletin of the London Mathematical Society, 50 (3), pp.513-528, which has been published in final form at https://doi.org/10.1112/blms.12156. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.