here is a short list of some additional reading (only titles in English, somewhat outdated but I do not have time to update it). I'll send you offline a more extended list. Hope this helps. I mark
those with an asterisks which I find especially useful for your purpose:
Burghart, Richard (1987), "Gifts to the gods: power, prosperity and ceremonial in Nepal", in: D. Cannadine and S. Price (eds.), Rituals of Royalty - Power and Ceremonial in Traditional Societies, Cambridge:
Cambridge University Press, pp. 237-270.
Kumar, Satish (1967), Rana Polity in Nepal - Origin and Growth. London: Asia Publishing House.
Regmi, Mahesh Chandra (1976), Landownership in Nepal. Berkeley, Los Angeles, London: University of California Press.
Stiller, Ludwig F. (1976), The Silent Cry - The People of Nepal 1816-1839. Kathmandu: Sahoyogi Press.
--- 1989. Prithivinarayan Shah in the Light of Dibya Upadesh. Kathmandu: Himalayan Book Centre (reprint, 1st ed. Ranchi 1968).
Whelpton, John. 1983. Jang Bahadur in Europe. Kathmandu: Sahayogi Press.
* ---. 1992. Kings, Soldiers and Priests: Nepalese Politics and the Rise of Jang Bahadur Rana, 1830-1857. Kathmandu:
Ratna Pustak Bhandar.
Society and Law
Bennett, Lynn (1983), Dangerous Wives and Sacred Sisters - Social and Symbolic Roles of High-Caste Women in Nepal. New York: Columbia University Press.
*Höfer, Andras. 1979. The Caste Hierarchy and the State in Nepal - A Study of the Muluki Ain of 1854.
Innsbruck: Universitätsverlag Wagner (Khumbu Himal, 13/2).
Michaels, Axel. 1993 "Widow burning in Nepal", in: Gerard Toffin (ed.), Nepal, Past and Present. Proceedings of the Franco-German Conference Art-et-Senans, June 1990.
Paris: CNRS Editions, pp. 21-34.
---. 1994a. "The Legislation of Widow Burning in 19th-Century Nepal. Edition and Translation of the Chapter Satijānyako of
the Mulukī Ain", Asiatische Studien XLVIII.4: 1213-1240.
---. 1997a. "The King and the Cow. On a Crucial Symbol of Hinduization", in: David Gellner, Joanna Pfaff-Czarnecka and John Whelpton (eds.), Nationalism
and Ethnicity in a Hindu Kingdom: The Politics of Culture in Contemporary Nepal. Amsterdam: Harwood Academic Publishers, 79-100.
Art
Gutschow, Niels, The Nepalese Caitya - 1500 Years of Buddhist Votive Architecture in the Kathmandu Valley. With Drawings by Bijay Basukala and
an Introductory Essay on Newar Buddhism by David Gellner, Stuttgart 1997.
---. Architecture of Nepal, 3 vols. 2012.
-- and Bernhard Kölver, Bhaktapur - Ordered Space, Concepts and Functions in a Town of Nepal. Wiesbaden:
Steiner, 1975.
*Michael Hutt: Nepal. A Guide to the Art and Architecture of the Kathmandu Valley, Gartmore 1994.
*Slusser, Mary Shepherd (1982), Nepal Mandala - A Cultural Study of the Kathmandu Valley. 2 Vols., Princeton: Princeton University Press.
Religion
Anderson, Mary M. (1971), The Festivals of Nepal. London: Allen & Unwin.
*Gellner, David: Monk, Householder, and Tantrik Priest. Newar Buddhism and its Hierarchy of Ritual. Cambridge: Cambridge Univ. Press, 1992.
*Levy, Robert. (1990), Mesocosm - Hinduism and the Organization of a Traditional Newar City in Nepal. Berkeley:
Univ. of California Press.
Locke, John K. (1980), Karunamaya - The Cult of Avalokiteśvara- Matsyendranāth in the Valley of Nepal. Kathmandu:
Sahayogi Prakashan.
Michaels, Axel. Śiva in Trouble – Festivals and Rituals at the Paśupatinātha Temple of Deopatan (Nepal). Oxford,
New York: Oxford University Press, 2008.
---- (2005). (with Niels Gutschow) Handling
Death. The Dynamics of Death and Ancestor Rituals Among the Newars of Bhaktapur, Nepal. With Contributions by Johanna Buss and Nutan Sharma and a Film on DVD by Christian Bau. Wiesbaden:
Harrassowitz Verlag (Ethno-Indology; 3).
---. 2008. (with Niels Gutschow) Growing Up – Hindu and Buddhist Initiation Rituals among Newar Children in Bhaktapur, Nepal. With
a Film on DVD by Christian Bau. Wiesbaden: Harrassowitz Verlag (Ethno-Indology; 6).
---. (2012) (with Niels Gutschow) Getting Married
– Hindu and Buddhist Marriage Rituals among Newars of Bhaktapur and Patan, Nepal. With a Film on DVD by Christian Bau. Wiesbaden:
Harrassowitz Verlag (Ethno-Indology; 12).
Conference volumes:
Chr. von Fürer-Haimendorf (Ed.), The Anthropology of Nepal. Warminster:
Aris & Philips, 1974
Hitchcock, John T., and Rex L. Jone (eds.): Spirit
Possession in the Nepal Himalayas. Warminster (Engl.): Aris and Phillips, 1976.
Allen, Michael, and S.N. Mukherjee (eds.), Women in India and Nepal. Canberra:
ANU, 1982.
Kölver, Bernhard (ed.). 1986. Formen kulturellen Wandels
und andere Beiträge zur Erforschung des Himālaya. Sankt Augustin:
VGH Wissenschaftsverlag.
--- (ed.) 1992. Aspects
of Nepalese Traditions. Stuttgart: Franz Steiner Verlag.
Gutschow, Niels; Michaels, Axel (eds.). 1987. Heritage
of the Kathmandu Valley: Proceedings of an International Conference in Lübeck, 1987. Sankt Augustin: VGH Wissenschaftsverlag
Kölver, Bernhard (Ed.)
(1992), "Seminar on German Research on Nepal" in Kathmandu, March 12-15, 1990.Kathmandu: Nepal research Centree.
Brauen, Martin; Ramble, Charles (eds.). 1993. Anthropology
of Tibet and the Himalaya. Zurich: Ethnological Museum of the University of Zurich
Toffin, Gerard (ed). 1993. Nepal, Past and Present:
Proceedings of the Franco-German Conference Art-et-Senans, June 1990. Paris: CNRS Editions, 21-34.
Blondeau, Anne-Marie; Steinkellner, Ernst (eds.). 1996. Reflections of the Mountain.
Essays on the History and Social Meaning of the Mountain Cult in Tibet and the Himalaya. Wien: Verlag der Österreichischen Akademie der Wissenschaften.
Michaels, Axel, Cornelia Vogelsanger, Annette Wilke (eds.), Wild
Godesses in India and Nepal, Berne 1996.
Lienhard, Siegfried (ed.). 1996. Change and Continuity:
Studies in the Nepalese Culture of the Kathmandu Valley. Turin: Edizioni Dell'orso (CESMEO).
Bickel, Balthasar; Gaenszle, Martin (eds.). 1999. Cultural
Horizons and Practices in Himalayan Space. Zurich: Ethnological Museum of the University of Zurich.
Gutschow, Niels, Axel Michaels, Charles Ramble, Ernst Steinkellner (Hrsg.),Sacred Landscape of the Himalaya. Wien:
Österreichische Akademie der Wissenschaften, 2003.