Found the following article online, use it to answer the question: What was the last name of the art historian who stated that  the Kailasanath temple is considered an unrivalled work of rock architecture?  The Rashtrakutas contributed much to the architectural heritage of the Deccan. Art historian Adam Hardy categorizes their building activity into three schools: Ellora, around Badami, Aihole and Pattadakal, and at Sirval near Gulbarga. The Rashtrakuta contributions to art and architecture are reflected in the splendid rock-cut cave temples at Ellora and Elephanta, areas also occupied by Jain monks, located in present-day Maharashtra. The Ellora site was originally part of a complex of 34 Buddhist caves probably created in the first half of the 6th century whose structural details show Pandyan influence. Cave temples occupied by Hindus are from later periods.The Rashtrakutas renovated these Buddhist caves and re-dedicated the rock-cut shrines. Amoghavarsha I espoused Jainism and there are five Jain cave temples at Ellora ascribed to his period. The most extensive and sumptuous of the Rashtrakuta works at Ellora is their creation of the monolithic Kailasanath Temple, a splendid achievement confirming the "Balhara" status as "one among the four principal Kings of the world". The walls of the temple have marvellous sculptures from Hindu mythology including Ravana, Shiva and Parvathi while the ceilings have paintings. The Kailasanath Temple project was commissioned by King Krishna I after the Rashtrakuta rule had spread into South India from the Deccan. The architectural style used is Karnata Dravida according to Adam Hardy. It does not contain any of the Shikharas common to the Nagara style and was built on the same lines as the Virupaksha temple at Pattadakal in Karnataka. According to art historian Vincent Smith, the achievement at the Kailasanath temple is considered an architectural consummation of the monolithic rock-cut temple and deserves to be considered one of the wonders of the world. According to art historian Percy Brown, as an accomplishment of art, the Kailasanath temple is considered an unrivalled work of rock architecture, a monument that has always excited and astonished travellers.While some...
Brown