Silaban, V. S., H. Rahman, and D. H. Syah. “Expert Advisor Construction Using Fixed Fractional Money Management and Williams Percent-R Indicator In DAX-30 (DE30) Trading: Analysis on Zero Spread Account”. Economic: Journal Economic and Business, vol. 4, no. 4, Sept. 2025, pp. 607-15, doi:10.56495/ejeb.v4i4.1208.