Occlusion Culling
http://cg.cs.uni-bonn.de/en/publications/paper-details/guthe-2006-neal-optimal/
http://http.developer.nvidia.com/GPUGems/gpugems_ch29.html
http://s09.idav.ucdavis.edu/talks/04-JAndersson-ParallelFrostbite-Siggraph09.pdf
http://en.wikipedia.org/wiki/Hidden_surface_determination
http://software.intel.com/en-us/blogs/2013/03/22/software-occlusion-culling-update
http://fgiesen.wordpress.com/2013/02/17/optimizing-sw-occlusion-culling-index/
http://stackoverflow.com/questions/4995652/3d-occlusion-culling
http://geck.bethsoft.com/index.php/Occlusion_Culling
http://www.slideshare.net/guerrillagames/practical-occlusion-culling-in-killzone-3
http://www.cs.unc.edu/~zhangh/hom.html
http://www.nickdarnell.com/2010/06/hierarchical-z-buffer-occlusion-culling/
http://www.billbaxter.com/projects/occlusion.html
http://blog.selfshadow.com/publications/practical-visibility/
http://www.scribd.com/doc/84778586/Oat-Tatarchuk-Froblins-Siggraph2008
http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter06.html
Ogre & Hardware Occlusion queries - http://www.ogre3d.org/tikiwiki/tiki-index.php?page=Hardware+Occlusion+Query
Slides -
http://www.slideshare.net/repii/parallel-graphics-in-frostbite-current-future-siggraph-2009-1860503
Research Docs -
http://wscg.zcu.cz/wscg2001/Papers_2001/R201.pdf
http://www.selfshadow.com/talks/rwc_gdc2010_v1.pdf
http://www.secondintention.com/files/GDC2011-Occlusion-Slides.pdf
http://www.lsi.upc.edu/~achica/teaching/Master/Visibility/session3/bittner-eg04-chcull.pdf
http://dcgi.felk.cvut.cz/home/havran/ARTICLES/269_ftp.pdf
http://www.cs.princeton.edu/courses/archive/spr01/cs598b/papers/greene93.pdf