$ dpkg-query -S zlib.h
linux-headers-2.6.38-8-generic: /usr/src/linux-headers-2.6.38-8-generic/include/config/crypto/zlib.h
linux-headers-2.6.38-8-generic: /usr/src/linux-headers-2.6.38-8-generic/include/linux/zlib.h
linux-headers-2.6.38-8-generic: /usr/src/linux-headers-2.6.38-8-generic/include/config/ubifs/fs/zlib.h
syslinux-common: /usr/lib/syslinux/com32/include/zlib.h
linux-headers-2.6.38-8: /usr/src/linux-headers-2.6.38-8/include/linux/zlib.h
linux-headers-2.6.38-8-generic: /usr/src/linux-headers-2.6.38-8-generic/include/config/jffs2/zlib.h


$ dpkg-query -W zlib1g
zlib1g	1:1.2.3.4.dfsg-3ubuntu3