Table 1 Link decay has been studied for several years in specific subject areas.

Biology & Medicine

Science curriculum web links

2000

515

[24]

Full text of 3 dermatology journals

1999-2004

1113

[11]

Sample of bibliographies being published on PubMed

2006

840

[2]

References made in the Annals of Emergency Medicine

2000, 2003, 2005

586

[25]

References in 5 biomedical informatics journals.

1999-2004

1049

[26]

MEDLINE titles & abstracts

1994-2006

10208

[1]*

Internet citations in 5 health care management journals from 2002-2004

2009-2010

2011

[14]

MEDLINE abstracts

1995-2007

7462

[3]*

Communications

Citations appearing in research articles in 6 leading communications journals

2000-2003

1600

[27]

Ecology

URLs appearing in the full text of 4 Ecological Society of America journals

1997-2005

2100

[28]

Law

Samples from a collection of born-digital law- and policy-related reports and documents

2007-2010

2372

[29]

Library/Information Science

Citations appearing in 3 leading Information Science journals

1997-2003

2516

[30]

Sample of citations appearing in library and information science journals

1999-2000

500

[18]

Social Sciences

URLs appearing in the full text of 2 well-respected historical journals

1999-2006

510

[31]

Citations from articles in the Chinese Social Sciences Index

1998-2007

44973

[5]*

Various

Random Collection of web URLs

1996

371

[15, 17]

Various

Citations in 3 highly circulated journals

2002-2003

672

[32]

Various

Supplementary information published in 6 top-cited journals

2000, 2003

585

[33]

Various

Citations from conference articles

1995-2003

1068

[34]

Various Collections

[35–38]