The phrase "a substantial article" is correct and usable in written English.
It can be used to describe an article that is significant in size, importance, or content.
Example: "The researcher published a substantial article on climate change that contributed greatly to the ongoing debate."
Alternatives: "a significant article" or "a considerable article".
(The New York Times wrote a substantial article about Mr. Jones on August 26).
The senior essay takes the form of a substantial article, no longer than 13,000 words, excluding footnotes and bibliography.
The two-term essay takes the form of a substantial article, not longer than 12,500 words (approximately forty to fifty double-spaced typewritten pages).
In March 1982 a substantial article by McManus appeared in the Bangor Daily News.
By the next paragraph of a substantial article, the real theme was introduced, how, "Once again, TV finds itself in another cultural hot zone".
This was followed, in 1966, by a substantial article on the house, Aladdin's Palace in Kensington by Handley-Read for Country Life.
The World Book has no "Barbie" entry, but does include a reference to Barbie as part of a fairly substantial article on "Dolls". The only information that is given is that the doll was introduced in 1959, that she has a large wardrobe, and in a different place, that dark-skinned Barbies were introduced in the 1980s.
His explanation draws from a substantial New York Times Magazine article in which Fred Vogelstein describes the convergence of company-wide risk-taking and engineering feats that resulted in the iPhone: It's hard to overstate the gamble Jobs took when he decided to unveil the iPhone back in January 2007.
Interspersed with his books he also published a number of substantial articles and monographs on this and other relevant topics.
As one of the first substantial articles in a mainstream publication to cast serious doubt on the whole Vietnam adventure, it had an immediate and explosive effect, infuriating both General Westmoreland and President Lyndon B. Johnson and planting seeds of doubt in the public mind.
But substantial articles appear on a regular basis.
