  The method for objective (based on Ritz principle only) and optimal
determination of electronic-vibro-rotational (rovibronic) term values from
meassured wavenumbers recently proposed in our previous paper is applied for
singlet electronic states of $^{11}$BH molecule, namely $X^1\Sigma^+$,
$A^1\Pi$, $C'^1\Delta$, $B^1\Sigma^+$, $C^1\Sigma^+$, $D^1\Pi$, $E^1\Sigma^+$,
$F^1\Sigma^+$, $G^1\Pi$, $H^1\Delta$, $I^1\Sigma^+$, $J^1\Sigma^+$. All known
to authors experimental data on the wavenumbers of rovibronic spectral lines
are used. Those are the wavenumber values of 1563 spectral lines of 15 band
systems, obtained in 10 different original papers. As a result 529 term values
with their standard deviations were derived.
