  Radial-velocity measurements and sine-curve fits to the orbital radial
velocity variations are presented for ten close binary systems: TZ Boo, VW Boo,
EL Boo, VZ CVn, GK Cep, RW Com, V2610 Oph, V1387 Ori, AU Ser, and FT UMa. Our
spectroscopy revealed two quadruple systems, TZ Boo and V2610 Oph, while three
stars showing small photometric amplitudes, EL Boo, V1387 Ori, and FT UMa, were
found to be triple systems. GK Cep is close binary with a faint third
component.
  While most of the studied eclipsing systems are contact binaries, VZ CVn and
GK Cep are detached or semi-detached double-lined binaries, and EL Boo, V1387
Ori and FT UMa are close binaries of uncertain binary type. The large fraction
of triple and quadruple systems found in this sample supports the hypothesis of
formation of close binaries in multiple stellar systems; it also demonstrates
that low photometric amplitude binaries are a fertile ground for further
discoveries of multiple systems.
