I've expressed my opinion several times - separate the two when the goal is either strength or endurance
But if you're into combining them into one workout, recent research (link here) indicates that performing strength training after endurance training results in the more favorable endocrine response than strength before endurance.
Be careful with this information, as no performance measures were taken. While strength training after endurance training resulted in higher serum concentrations of testosterone and IGFPB-3, it would be irrational to assume that this results in the greatest performance gains - and at what performance measures: strength vs cardiovascular endurance.
At the end of the day, more work completed = more muscle damage and more energy expended.