Возможно, это просто артефакт перевода на русский.
Вот статья (Curt Renshaw; последняя редакция статьи - не ранее 1997):
http://renshaw.teleinc.com/papers/pegrav/pegrav.stm
http://renshaw.teleinc.com/papers/pegrav/pegrav.doc
А вот цитаты из нее:
Цитата:
There have been no less than four very strong attempts to produce a velocity dependent form of the gravitational potential, most notably developed by Gerber, Weber, Maxwell and Ritz. Interestingly, with the exception of Einstein's theory of general relativity, every such attempt failed either in accommodating Mercury's anomaly, or photon deflection, or both.
Цитата:
Paul Gerber came very close to deriving an appropriate potential calculating the motion of the bodies during the time required for the force to propagate between them, but failed to fully justify his approach. He died shortly after its publication, and his method was later found to produce a value for photon deflection one and one-half times greater than the accepted value.
Дополнение: в статье есть ссылка на книгу:
5. Roseveare, N. T., Mercury’s Perihelion from Le Verrier to Einstein, (Oxford, New York, 1982).
Книга оценивается как "An excellent treatise". Цитаты - сразу после ссылки.