J. Donoghue. (2022)cite arxiv:2211.09902Comment: 27 Pages. Invited chapter for the Section "Effective Quantum Gravity" of the "Handbook of Quantum Gravity" (Eds. C. Bambi, L. Modesto and I.L. Shapiro, Springer Singapore, expected in 2023).
R. MacKenzie. (2000)cite arxiv:quant-ph/0004090
Comment: 55 pages, 23 figures. Lectures given at Rencontres du Vietnam: VIth
Vietnam School of Physics, Vung Tau, Vietnam, 27 December 1999 - 8 January
2000.