1.	Introduction	2
2.	Forced Vibrations, Complex Resonance Frequencies	6
3.	Techniques of Read-Out	8
3.1.	Oscillator Circuits	9
3.2.	Impedance Analysis	9
3.3.	Ring-Down	10
3.4.	Multi-Frequency Lock-In Amplification	10
3.5.	Fast Measurements, Modulation Experiments	11
3.6.	Noise and Drift	13
4.	The Acoustic Multilayer Formalism and its Consequences	14
4.1.	Qualitative Data inspection	14
4.2.	The Small-Load Approximation in 1D (Parallel-Plate Model)	14
4.3.	Inertial Loading	17
4.4.	Semi-Infinite Viscoelastic Media	17
4.5.	Films in Air	21
4.5.1.	Very Thin Films (Sauerbrey Limit)	23
4.5.2.	Infinite Thickness	23
4.5.3.	Thin Viscoelastic Films	23
4.5.4.	The Film Resonance	25
4.6.	Layers Adsorbed from a Liquid Phase	27
4.6.1.	General	27
4.6.2.	Thin Adsorbates	28
4.6.3.	Thick Layers	32
4.7.	Viscoelastic Dispersion and High-Frequency Rheology	33
4.8.	Slip	34
5.	Non-Planar Samples	35
5.1.	Point Contacts with Large Objects Clamped in Space by Inertia	35
5.2.	Large Amplitudes, Partial Slip	36
5.3.	Structured Samples, Numerical Calculations	40
5.4.	Roughness	42
6.	Coupled Resonances	43
6.1.	The Sphere with Moderate Mass	43
6.2.	Influence of Rotation on the Frequency Shift	46
6.3.	Other Types of Coupled Resonances	49
7.	Piezoelectric Stiffening	50
8.	Beyond the Parallel-Plate Model	51
8.1.	Energy Trapping, Compressional Waves	51
8.2.	Anharmonic Sidebands	54
8.3.	Towards 3D-Modelling: The Small-Load Approximation in Tensor Form	55
8.4.	The 4-Element Circuit and the Electromechanical Analogy	58
8.5.	Amplitude of Oscillation, Effective Area	60
8.6.	Modal Mass, Sauerbrey Equation for Plates with Energy Trapping	61
9.	Combined Instruments	62
9.1.	The Electrochemical QCM (EQCM)	63
9.2.	Combination with Optical Reflectometry	63
References		71