Simple two-electrode biosignal amplifier. - Dobromir Petkov Dobrev; Tatyana Neycheva; Nikolay Mudrov (Medical Biol. Eng. Comput., 2005)

Bootstrapped two-electrode biosignal amplifier. - Dobromir Petkov Dobrev; Tatyana Neycheva; Nikolay Mudrov (Medical Biol. Eng. Comput., 2008)

High-quality biopotential acquisition without a reference electrode: power-line interference reduction by adaptive impedance balancing in a mixed analog-digital design. - Dobromir Petkov Dobrev; Tatyana Neycheva (Medical Biol. Eng. Comput., 2022)