Poltergeist 

I see you have removed the link I recently added to the poltergeist article. Your justification for this is "fringe paper in a psychic journal on 'strange' sounds, I don't see why this is relevant to this article." Let's examine that step by step.

(1) Fringe paper. The paper is by Dr Barrie G. Colvin. This is what Bloomberg Business says about him:

Dr. Barrie G. Colvin is the founder and Managing Director of IFS Chemicals Ltd. Dr. Barrie Colvin is a polyurethane technologist with significant experience in the formulated systems market in Europe. He attended the University of Manchester Institute of Science & Technology and obtained a B.Sc. (Honours) degree in Polymer Technology (Chemistry). Following three years of research in the area of X-ray crystallography of polymers, he was awarded a Ph.D. from the same University. In 1973, Barrie Colvin joined Shell Research Ltd. as a polyurethane technologist, specialising in fire-retardant foams and new generation appliance insulation. In 1975, he worked on the development of base polyols for rigid foam applications followed by several years as Technical Manager for a polyurethane systems house in the UK. In 1982, Barrie Colvin founded IFS, a polyurethane formulating company, specialising in rigid and semi-rigid foams as well as speciality elastomers. The IFS Group is committed to the development of more environmentally acceptable polyurethane chemicals, having introduced a zero ODP insulation foam to the commercial refrigeration market in 1988. More recently, the company has successfully implemented the use of polyols based upon natural oils.

And this is his profile on LinkedIn:

As the principal shareholder (90%) in IFS Chemicals, Envirofoam Chemicals and Bollards International, my main activities centre around the development and manufacture of bespoke chemical systems for a wide variety of industries. My principal expertise is in the formulation of polyurethanes for industrial applications, ranging from insulation products, automotive mouldings, sub-sea pipeline protection systems, various marine applications etc. I have done this type of work all my working life (40 years) and continue to remain very hands-on in the laboratory development of newer, improved systems. The success of these companies can be attributed to the dedication of the staff at our factory in Roydon, Norfolk. Our aim to to [sic] provide customers with the very best, bespoke product for their intended application, backed up by the very best, most experienced field engineers who help to turn chemicals into products.

An equally important part of my time involves my participation within the Society for Psychical Research. This organization gets involved with the scientific study of claims of paranormal activity and over the years has included many eminent scientists, including a number of Nobel prizewinners. Many members of the Society have come to recognize that the known laws of physics cannot explain some of the more unusual phenomena that have been shown to exist in the world around us. As an example, there is a wealth of evidence supporting the objective nature of psychokinesis but, as yet, there is no generally accepted theory of how "mind-over-matter" might work. I am a member of the Council of the Society for Psychical Research and have been very actively involved with the Spontaneous Cases Committee for some years. Whilst I have been involved with many aspects of the paranormal, my main interest is in the area of poltergeist activity (also known as RSPK—Recurrent Spontaneous PsychoKinesis).

(2) Psychic journal. I think I detect a note of disdain. The paper appeared in the Journal of the Society for Psychical Research. As indicated by Dr Colvin in his LinkedIn profile, the Society for Psychical Research is dedicated to the scientific study of allegedly paranormal phenomena and its membership has over the years included many eminent scientists, among them a number of Nobel laureates.

(3) Strange sounds. Did you read the paper? The strange sounds in question are poltergeist rappings.

I am going to restore the link and would be grateful if you would let it stand.