Kaptein–Closs rules

https://doi.org/10.1351/goldbook.K03369
Rules used to predict the sign of CIDNP effects.
Source:
PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2250 (https://doi.org/10.1351/pac199668122223)