The source you really want to use for nutrition information is the USDA National Nutrient Database.
See http://ndb.nal.usda.gov/ndb/foods/show/6359?fg=&man=&lfacet=... and http://ndb.nal.usda.gov/ndb/foods/show/1866
See http://ndb.nal.usda.gov/ndb/foods/show/6359?fg=&man=&lfacet=... and http://ndb.nal.usda.gov/ndb/foods/show/1866
http://food.vegtalk.org/nutrients/cereals/protein.html
It shows that some products, like wheat durum are richer in proteins but with the almost the same amount of calories.