tl;dr : Unfortunately no; and yes that range is about as good as you will find. Though I would say 50-100 million is generally accepted now.

The estimates that began to circulate during the 1920s pegged the global total at around 30 million and so thats pretty much the baseline for most studies of the Spanish flu. Over the past hundred years, the number of deaths attributed to the Spanish flu have been revised upwards-- this is really a product of better disease modeling and the slow trickle of historical research that has highlighted the unimaginable human cost of the outbreak.

Recent studies have revised the number of dead from 30 million to 50 million and Johnson and Mueller estimate it is entirely possible that the real total may be as high as 100 million. They argue many locals government services virtually ground to a halt during the outbreak so that deaths were registered only haphazardly and colonial officials burdened with deadlines to submit reports attributed deaths to pneumonia or other illnesses with similar symptoms. Victims of the Spanish flu suffered fever, severe headaches, body pains, coughing of blood and nose bleeds. Many died when bacteria invaded the lungs, filling them with fluid and effectively drowning them or from accompanying bouts of pneumonia. So deaths coud be attributed to any number of different factors-- if they were even recorded at all.

• Alfred W. Crosby, America’s Forgotten Pandemic; The Influenza of 1918 (Cambridge: Cambridge University Press, 2003).

• David Killingray, ‘“Imperial Disease”: The Influenza Pandemic of 1918-9 and its Impact on the British Empire’, Caribbean Quarterly, 49:3 (2003).

• Niall P.A.S. Johnson and Juergen Mueller, ‘Updating the Accounts: Global Mortality of the 1918-1920 “Spanish” Influenza Epidemic’, Bulletin of the History of Medicine, 76:1 (2002).