(1999). Keep active: Safe at any age.
Chicago-čujuhus (17. p.)Keep Active: Safe at Any Age. 1999.
MLA-čujuhus (9. p.)Keep Active: Safe at Any Age. 1999.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.
APA-čujuhus (7. p.)