I'm wondering if the following sentence is grammatically correct.
I've never seen a dumbest girl like this
A grammar book says the superlative should have the article "the". However, I found the above sentence on the internet which seems to be written by a native English speaker.
Dawnman Planet by Mack Reynolds https://books.google.co.jp/books?id=bX85CeGtwqgC&pg=PT8&dq=%22a+slightest%22&hl=ja&sa=X&ved=0ahUKEwjP97Lz0sPLAhXFE5QKHRFtBOg4KBDoAQgaMAA#v=onepage&q=%22a%20slightest%22&f=false
The galaxy is immense, and thus far, we have but touched a slightest segment of it.
Mack Reynolds was an American science fiction writer. https://en.wikipedia.org/wiki/Mack_Reynolds
A Mother's Secret by Scarlet Wilson https://books.google.co.jp/books?id=GF51AgAAQBAJ&pg=PT38&dq=%22a+slightest%22&hl=ja&sa=X&ved=0ahUKEwjTuvOFjMTLAhVjKKYKHRJJCno4HhDoAQgiMAE#v=onepage&q=%22a%20slightest%22&f=false
"So what do you think?" He spun around in his chair until he faced her, leaning forward, his elbows on his knees, giving her a slightest glimpse of his dark curled hair at the base of his throat.
About the author http://www.scarlet-wilson.com/1_3_Bio.html
Ulverton by Adam Thorpe
This room grows so tedious and fusty. Because I have a slightest of fevers I am to be confined a further week upon the end of the month.
About the author https://en.wikipedia.org/wiki/Adam_Thorpe
Edit (March 20, 2016) I have posted a similar question here: https://english.stackexchange.com/questions/314773/is-a-slightest-glimpse-gramatically-incorrect