A fine still valid resource in my opinion are the two volumes by French author and art critic Bernard Dorival (1914-2003) titled Twentieth Century Painters published in 1958 by the Editions Pierre Tisne in Paris and in the same year by Universe Books in New York, translated from the French by W. J. Strachan a well known translator and writer.
The two volumes are beautifully bound in cloth with a tipped in plate pasted to the front of the cloth binding. In the first volume Dorival covers the Nabis, Fauves and Cubists painters and in the second volume the painters coming to the scene after WWII, like Tal Coat, Gustave Singier, Alfred Manessier, Deyrolle, Soulages, Lanskoy and others.
The printing is exceptional and the tipped in plates are fine photographic reproductions. Each volume closes with a bibliography and artists biographies superior in many cases than what you find on the internet. Dorival discusses the lesser known artists, not only those that are generally familiar to us. His information is always, concise and firsthand, having held a post as curator he counted many artists among his friends. Here are some impressions of the books.