On opening the above URL (you might have to reload the page a few times to get the text to appear - this might be another bug) you'll find that the last five results, being:

[[Image:3 accelerators 17-59. PILCURE-MBT,MBTS,ZMBT,F,CBS,NS,MOR,DCBS,TMT,ZDMC,ZDC,ZDBC,SDBC,ZDBzC-.pdf]]

[[Image:Minnesota Educational Computing Consortium Quick Reference Guide for BASIC Language Version 3.1 MECC TIMESHARE SYSTEM Rev. 2 slash 78.pdf]]

[[Image:Partial unilateral ureteropelvic obstruction in neonatal pigs - Effect of acute inhibition of angiotensin II AT1-receptors on GFR and sodium handling.pdf]]

[[Image:Strategy for improving genetic aspects of fertility and hatchability in breeding lines of White Leghorns, and choosing hens for second cycle of production.pdf]]

[[Image:Buddha's teachings in a NUTSHELL(Explains why Buddha did not answer Questions pertaining to eternal God, NON-SOUL theory (anatta) and his basic teachings.pdf]]

... as well as various others, are deleted and have been so for quite a long time. Deleted items should not appear in search results.

The user interface search - url: http://en.wikipedia.org/w/index.php?title=Special:Search&limit=500&offset=7000&ns6=1&redirs=1&search=.pdf (once again, you might have to reload multiple times) - is somewhat better behaved as in it doesn't show these deleted items but when you view the page source you find comments such as:

<!-- missing page Image:3 accelerators 17-59. PILCURE-MBT,MBTS,ZMBT,F,CBS,NS,MOR,DCBS,TMT,ZDMC,ZDC,ZDBC,SDBC,ZDBzC-.pdf-->
<!-- missing page Image:Minnesota Educational Computing Consortium Quick Reference Guide for BASIC Language Version 3.1 MECC TIMESHARE SYSTEM Rev. 2 slash 78.pdf-->
<!-- missing page Image:Partial unilateral ureteropelvic obstruction in neonatal pigs - Effect of acute inhibition of angiotensin II AT1-receptors on GFR and sodium handling.pdf-->
<!-- missing page Image:Strategy for improving genetic aspects of fertility and hatchability in breeding lines of White Leghorns, and choosing hens for second cycle of production.pdf-->
<!-- missing page Image:Buddha's teachings in a NUTSHELL(Explains why Buddha did not answer Questions pertaining to eternal God, NON-SOUL theory (anatta) and his basic teachings.pdf-->

Version: unspecified
Severity: normal
URL: http://en.wikipedia.org/w/api.php?action=query&list=search&srwhat=text&srsearch=.pdf&srnamespace=6&sroffset=7000&srlimit=500