Tolong jelaskan mengenai Rujukan dari PyPy

Davide Ancona, Massimo Ancona, Antonio Cuni, Nicholas D. Matsakis, 2007. RPython: a Step Towards Reconciling Dynamically and Statically Typed OO Languages. In Proc. Dynamic Language Symposium (DLS), 2007. ACM Press.

Carl Friedrich Bolz, Antonio Cuni, Maciej Fijalkowski, 2009. Tracing the meta-level: PyPy's Tracing JIT Compiler . In Proc. ICOOOLPS, 2009. ACM Press.