Hi Guys,
Here is what one of the english grammar site has to say about this point.
-------------------------------------------------------------------------------
A disputed point.
415. This prepares the way for the consideration of one of the vexed questions,—whether we should say, "one of the finest books that has been published," or, "one of the finest books that have been published."
One of ... [ plural] that who, or which ... [ singular or plural. ]
Both constructions are frequently found, the reason being a difference of opinion as to the antecedent. Some consider it to be one [book] of the finest books, with one as the principal word, the true antecedent; others regard books as the antecedent, and write the verb in the plural. The latter is rather more frequent, but the former has good authority.
The following quotations show both sides:—
Plural.
He was one of the very few commanders who appear to have shown equal skill in directing a campaign, in winning a battle, and in improving a victory. —Lecky.
He was one of the most distinguished scientists who have ever lived. —J. T. Morse, Jr ., Franklin.
It is one of those periods which shine with an unnatural and delusive splendor. —Macaulay.
A very little encouragement brought back one of those overflows which make one more ashamed, etc. —Holmes.
I am one of those who believe that the real will never find an irremovable basis till it rests on the ideal. —Lowell.
French literature of the eighteenth century, one of the most powerful agencies that have ever existed.— M. Arnold .
What man's life is not overtaken by one or more of those tornadoes that send us out of our course? —Thackeray.
He is one of those that deserve very well. —Addison.
Singular.
The fiery youth ... struck down one of those who was pressing hardest. —Scott.
He appeared to me one of the noblest creatures that ever was, when he derided the shams of society. —Howells.
A rare Roundabout performance,—one of the very best that has ever appeared in this series. —Thackeray.
Valancourt was the hero of one of the most famous romances which ever was published in this country.— Id.
It is one of the errors which has been diligently propagated by designing writers. —Irving.
"I am going to breakfast with one of these fellows who is at the Piazza Hotel." —Dickens.
The "Economy of the Animal Kingdom" is one of those books which is an honor to the human race. —Emerson.
Tom Puzzle is one of the most eminent immethodical disputants of any that has fallen under my observation. —Addison.
The richly canopied monument of one of the most earnest souls that ever gave itself to the arts. —Ruskin.
-----------------------------------------------------------------------
Here is the link if you are interested in reading whole thing about relative pronouns
https://classiclit.about.com/library/bl- ... onouns.htm
