10+ Kapotasana Yoga Journal. The pose is not found in medieval hatha yoga texts. Kino macgregor deconstructs how to safely enter the advanced backbend in yogapedia:

Eka or one pada or foot/leg nindra or standing raja or king kapota or pigeon, and asana or pose as with all backward bends, this pose creates a nice opening in the chest and strengthens the back and hip area. These articles were all first published by yoga journal magazine. The rahaysa is probably the first book to discuss yoga for women.it specifically addresses women's needs and gives us a yoga for pregnancy.
See also kino macgregor challenge pose:
Bend the right leg and keep the left leg straight. See more ideas about kapotasana, iyengar yoga, yoga asanas. These articles were all first published by yoga journal magazine. Helen's latest post on ashtanga yoga journal features a very powerful and honest discussion of the trials and tribulations of working with this very powerful post.