This is a file from the Wikimedia Commons. Information from its description page there is shown below. Commons is a freely licensed media file repository. You can help.
Summary
DescriptionSpanish vowel chart.svg
English: Spanish vowel chart.
Date
Source
Own work, based on a vowel chart in Ladefoged, Peter; Johnson, Keith (1975) A Course in Phonetics, 6th edition, Boston, MA: Wadsworth, published 2010, page 227
This vector image includes elements that have been taken or adapted from this file:
IPA vowel trapezium.svg (by Moxfyre).
This vector image includes elements that have been taken or adapted from this file:
Ga open allophones.svg (by Angr).
Author
IPA_vowel_trapezium.svg: Moxfyre (talk)
Ga_open_allophones.svg: Angr: (talk)
derivative work: Mr KEBAB (talk)
Licensing
I, the copyright holder of this work, hereby publish it under the following license:
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
You are free:
to share – to copy, distribute and transmit the work
to remix – to adapt the work
Under the following conditions:
attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.