Hudson, J. H. (2000) “Pigmy-weed (Crassula aquatica (L.) Shoeni.) and spurrey knotweed (Polygonum spergulariaeforme Meisn.) new to Saskatcewan, and comments on five other rarities found 1998-1999”, Blue Jay, 58(3). doi: 10.29173/bluejay5949.