  We present a review of our results for the masses and couplings of the scalar
fully heavy four-quarks and $T_{QQ\bar{q}\bar{q}'}\, (J^P=0^\pm , 1^\pm)$
tetraquarks states from QCD Laplace sum rule (LSR), their ratios ${\cal R}$ and
double ratio of sum rules (DRSR) within stability criteria and including
Factorized Next-to-Leading Order (FNLO) Perturbative (PT) corrections. As the
Operator Product Expansion (OPE) usually converges for $d\leqslant 6-8$, we
evaluated the QCD spectral functions at Lowest Order of PT QCD and up to
$\langle G^3 \rangle$. Our results for the $0^{++}$ fully heavy four-quark
states may explain the LHCb broad structure around (6.2-6.7)GeV which can be
due to $\overline{\eta_c} \eta_c,~~ \overline{\chi_{c1}}\chi_{c1}$ and
$\overline{J/\psi}J/\psi$ molecules or/and their analogue $S_c S_c,~~ A_cA_c$
and $V_cV_c$ tetraquarks. The peak at (6.8-6.9)GeV can be identified to the
$\overline{\chi_{c0}}\chi_{c0}$ molecule or/and the $P_c P_c$ tetraquark state.
Then, combining ${\cal R}$ and DRSR we focus on the analysis of the four-quark
nature of $T_{cc\bar{q}\bar{q}'}$ $1^{\pm}$ and $0^{\pm}$ states. We show that
combining ${\cal R}$ and DRSR can provide more precise results:
$M_{T^{1^+}_{cc}}=3886(6)$MeV and $M_{T^{0^+}_{cc}}=3883(3)$MeV. From our
estimates of the masses of the Pseudoscalar and Vector $T_{cc\bar{q}\bar{q}'}$
states, we observe that the interpolating currents lead to two classes: Class H
(Heavy) states with masses around 6GeV and Class L (Light) states around
(3.8-4.4)GeV where the pseudoscalar (resp. all vector states) are below the
$\overline{D}D_0,~~ overline{D}_s D_{s0}$ (resp. $\overline{D}D_1,~~
\overline{D}_s D_{s1}$) open charm thresholds. Finally, we extend the whole
study to the bottom sector and confront our results with the ones from
different LSR predictions and some other approaches in the literature.
