https://research.ibm.com/publications/photoisomerization-of-certain-stilbenes-to-910-dihydrophenanthrenes
Photoisomerization of Certain Stilbenes to 9,10-Dihydrophenanthrenes for JACS - IBM Research
Photoisomerization of Certain Stilbenes to 9,10-Dihydrophenanthrenes for JACS by R. Srinivasan et al.