I don't know if there is an explicit reference, but there is sort of an implied teaching of that when causation is discussed.
For example, the five levels of cause and effect:
Non-living matter (physical world), Seed (biological world), Mind (psychological), Kamma, Dhamma
(Note that kamma is only one of the levels of cause and effect and does not explain everything.)
There are many causes and effects listed in the Tipitaka, especially the Abhidhamma, which I think implies no singular effects, which by the way is compatible with modern psychology and the social sciences with their use of examining multiple causes and effects, probability, factor analysis, and spurious relationships.
The Paṭṭhāna book of the Abhidhamma goes into detail about the
24 causal relations.