That raised a suggestion in an article in U.S. News and World Report magazine that the company had possibly used insider information.
Questions about the trips' financing were first raised in March in an article in the National Journal.
Concerns about the fund's procedures were raised most recently in an article that appeared last year on Africana.com, an Internet site focused on African-American lifestyles.
The issue of the real identity of the artist was raised in an article in 1934 by G. Marlier.
In 2011, he raised the issue of palm oil in kosher food in an article in the national newspaper The Jewish Chronicle.
This objection was raised by The Economist, in an article entitled "Artificial Stupidity" published shortly after the first Loebner prize competition in 1992.
The same concern is raised in an article in the journal 'Science', where the benefit of biofuels to climate is compared with afforestation over a 30-year period.
The possibility of his resignation was raised in an article yesterday in The New York Post.
GQ magazine raised the issue several years ago in an article titled "Smart People, Dumb TV."
The student, Timothy Maguire, raised the issue last week in an article in The Georgetown Law Weekly, a publication managed by students.