This is not an exhaustive list but still makes a great start, enjoy!  

Ask about borrowing from the Learn Out There library!

Begon, M.,  Harper, J.,  Townsend, C. (1996).  Ecology: Individuals, populations and communities. 3rd Ed.  Blackwell Science Ltd.  Oxford.

Coopersmith, S. (1967).  The Antecents of Self-esteem.  San Francisco.   Freeman.

Cornell, J. (1998).  Sharing nature with children -2nd Edition.  Dawn publications.  California.

Drummond, M. J. (1993).  Assessing Children's Learning.   Routledge.  Oxon.

Faber, A. and Mazlish, E. (1995).  How to talk so kids can learn.  Picadilly Press Ltd.  London.

Goleman, D. (1995).  Emotional Intelligence.  Bantam. New York.

Kaiser, B. and Raminsky,  J. S. (2001). Challenging behaviour in young children. Boston, Massachusetts. Pearson.

Knight, S.  (2009).  Forest School and Outdoor Learning in the Early Years - 2nd edition.  Sage publications.  London.

Knight, S. ed (2011).  Forest School for All.  Sage publications.  London.

Little, H. (2006) Childrens risk taking behaviour: Implications for early childhood policy and practice. International Journal of Early Years Education, 1 (2) 141-154.

Louv, R. (2006).  Last Child in the Woods.  Algonquin Books.  New York.

Mabey, R. (1996).  Flora Britannica.  Sinclair Stevenson. London.

Mears, R. (2002).  Bushcraft: An Inspirational Guide to Surviving the Wilderness.  Hodder and Stoughton.  London.

Mitchell, A. (1985). The Complete Guide to Trees of Britain and Northern Europe.  Parkgate Books.  London.

Maynard,T. (2007) Encounters with forest school and Focault : A risky business ?. Education 3-13, 35 (4): 379-391.

National Childrens Bureau.  (2002).  Managing risk in play provision : A position statement 2002 (Play safety forum).

Palmer, S. (2006).  Toxic Childhood.  Orion. London

Penn, H. (2010) Does it matter what country you are in? In: S Smidt (ed) 1 Key Issues in Early Years Education ( 2nd edition). London: Routledge, pp 18-22. 

Pound, L. (2006).  How Children Learn, Book 1.  Practical Pre-school Books.  London.

Rackham, O. (1986). The History of the Countryside.  Phoenix Giant.  London.

Salovey, P., Mayer, J. (1990).  Emotional Intelligence.  Imagination, cognition and personality, 9(3), 185-211.

Shiraldi, G.R.  (2001).  The Self-Esteem Workbook.  New Harbinger Publications.  California.

Starr, C.  (2005).  Woodland Management - A Practical Guide.  Crowood Press.  Marlborough.

Stephenson, A. (2003) Physical Risk taking : dangerous or endangered. Early Years, 23 (1) : 35-43.

Sutherland, W. J. and Hill, D. A. (1995).  Managing Habitats for Conservation.  Cambridge University Press.

Sutherland, W. J. and Hill, D. A. (1998).  Conservation Science and Action.  Blackwell Science Ltd.  Oxford.

Waite, S. ed (2011).  Children Learning Outside the Classroom.  Sage Publications.  London.

Waters, Lea. (2014).  Newspaper article ‘Can we build a better child?’.  http://www.theage.com.au/victoria/can-we-build-a-better-child-20140301-33t4v.html

Waters,  J. and Begley, S. (2001) Supporting the development of risk taking behaviours in the early years : an exploratory study. Education. 3-13, 35 (4) : 365-377.