(EN) Stephan V. Beyer, Singing to the Plants: A Guide to Mestizo Shamanism in the Upper Amazon, Albuquerque, University of New Mexico Press, 2009, ISBN 978-0-8263-4729-9.
«some songs, such as calling in the spirit of ayahuasca at the start of a ceremony, are performed without rhythmic accompaniment, while healings are all performed with the shacapa.»
