Problems with getting due credit in publishing in academic chemistry

There’s coverage in the Times Higher Education  of a paper on the perception of academic credit among academic chemists in the US, published in the journal Accountability in Research in July 2010.
Acccording to the article  "Influences on Authorship Issues: An Evaluation of Receiving, Not Receiving, and Rejecting Credit" in the sample that responded “Fifty percent of the respondents reported not receiving appropriate credit for contributions they had made to published projects.”

However, it’s important to note that the 600 faculty members who responded represented 16% of the survey recipients. The article is not freely available (despite being marked open access) so I can’t assess whether they took such a responder bias into account. According the THES report “The study found that the perception of not receiving appropriate credit was independent of the respondent’s seniority, field of expertise and publication record."

If anyone who has read the full article can fill us in further that would be useful