Premaratne, W.A.P.J.2016-06-232016-06-232015Premaratne, W.A.P.J. 2015. Lesson 04: Determination of soil density and its compaction or porosity, In: Practical Manual for GCE A/L Biosystem Technology Teachers. Ministry of Education and University of Kelaniya, Sri Lanka. 21-23 pp.978-955-4563-50-6http://repository.kln.ac.lk/handle/123456789/13644enLearning Object