Missing pthread related man pages

man pthreads says:
SEE ALSO
       clone(2), futex(2), gettid(2), proc(5), futex(7), sigevent(7),
       signal(7),
       and various Pthreads manual pages, for example: pthread_attr_init(3),
       pthread_atfork(3), pthread_cancel(3), pthread_cleanup_push(3),
       pthread_cond_signal(3), pthread_cond_wait(3), pthread_create(3),
       pthread_detach(3), pthread_equal(3), pthread_exit(3),
       pthread_key_create(3), pthread_kill(3), pthread_mutex_lock(3),
       pthread_mutex_unlock(3), pthread_once(3), pthread_setcancelstate(3),
       pthread_setcanceltype(3), pthread_setspecific(3), pthread_sigmask(3),
       pthread_sigqueue(3), and pthread_testcancel(3)

However many of these don't exist. For example:

b:~:504$ man pthread_once
No manual entry for pthread_once
b:~:502$ man pthread_mutex_lock
No manual entry for pthread_mutex_lock
b:~:503$ man pthread_mutex_unlock
No manual entry for pthread_mutex_unlock
b:~:508$ man pthread_setspecific
No manual entry for pthread_setspecific
b:~:513$ man pthread_atfork
No manual entry for pthread_atfork
b:~:516$ man pthread_cond_signal
No manual entry for pthread_cond_signal
b:~:517$ man pthread_cond_wait
No manual entry for pthread_cond_wait

Also though not directly refereneced from there
b:~:520$ man pthread_mutex_init
No manual entry for pthread_mutex_init

Which exists in other places - eg: http://linux.die.net/man/3/pthread_mutex_lock

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: manpages 3.35-0.1ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-32.51-generic 3.2.30
Uname: Linux 3.2.0-32-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu14
Architecture: amd64
Date: Tue Nov 6 14:15:19 2012
Dependencies:

InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: manpages
UpgradeStatus: No upgrade log present (probably fresh install)