For example, the NIST Chinese-to-English and Arabic-to-English MT evaluation datasets (2003)(2004)(2005)(2006)(2007)(2008) have in total around 10,000 Chinese sentences and 10,000 Arabic sentences each with 4 different English translations.
for image captioning datasets, multiple references are more common not only for evaluation, but also for training, e.g., the MSCOCO (Lin et al., 2014) dataset provides 5 references per image and PASCAL-50S and ABSTRACT-50S (Vedantam et al., 2015) even provide 50 references per image.