But you can still get all the amino acids you need even by eating a variety of incomplete protein sources. (webmd.com)
If using incomplete protein foods such as whole grains / nuts, seeds / and legumes, you need to combine two foods from the three groups to make a complete protein. (theeasyhealthyway.com)
Some plant foods contain incomplete protein, which means they are low in certain essential amino acids [66]. (nutrientsreview.com)