Najmaei et al., 2012, considered the "thermal effects on the Raman spectra of molybdenum disulfide with thicknesses ranging from bulk to monolayer". The researchers "quantitatively determined the laser-induced heating effects on the peak position and the linewidth of the Raman spectrum. [Najmaei and coworkers] found considerable thickness-dependent red-shifts as well as line-width changes for both E 1 2g and A1g vibrating modes as laser power was increased". The results "demonstrate the important effects of the anharmonic terms in the lattice potential energy" An "intriguing anomalous behavior" has been observed by Ranjuna and Balakrishnan, 2021, "in the temperaturedependent Raman spectra of mono-, bi-, and trilayer molybdenum disulfide samples with sulfur vacancies, measured at high temperatures ranging from room temperature to 463 K". "In contrast to existing reports, Balakrishnan] observed a decrease in the FWHM of the A1g phonon mode, along with an increase in the relative intensity of the A1g mode to the E 1 2g mode, as the temperature increased. … These observations are explained by considering the presence of sulfur vacancies" .