[1] [CITE@en[Simple Feature Access - Part 2: SQL Option | OGC]]
([TIME[2017-06-05 12:15:39 +09:00]])
<http://www.opengeospatial.org/standards/sfs>

[2] [CITE@en[Simple Feature Access - Part 1: Common Architecture | OGC]]
([TIME[2017-06-05 12:15:56 +09:00]])
<http://www.opengeospatial.org/standards/sfa>

[3] [CITE@en[Simple Features - Wikipedia]]
([TIME[2017-05-24 12:34:37 +09:00]])
<https://en.wikipedia.org/wiki/Simple_Features>