You might also be interested in these books about mudras at Amazon

Mudras, by Gertrud Hirschi
Yoga in Your Hands

Mudras to heal physical, emotional and spiritual conditions. With clear drawings.

The Healing Power of Mudras, by Rajendar Menen
The Yoga of the Hands

Lots of background information on mudras.

Mudras for Body, Mind and Spirit, by Gertrud Hirschi
The Handy Course in Yoga [With 68 Cards for Practice]

Beautiful set of 68 cards with mudras.

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