Copy-on-write in the PHP language.

Akihiko Tozawa Michiaki Tatsubori Tamiya Onodera Yasuhiko Minamide Copy-on-write in the PHP language. 200-212 2009 POPL http://doi.acm.org/10.1145/1480881.1480908 conf/popl/2009 db/conf/popl/popl2009.html#TozawaTOM09