Abou the Parameters Ls, L0 and L2 of PMSM

Hello,

I’m watching the Permanent Magnet Synchronous Machine (4.6.7 Users manual),
I don’t understand how to compute Ls, L0 and L2 from Ld and Lq.
The User-s Manual p. 97 (psim 10) give only these 2 equations:
Ld = Ls + 3/2L0 + 3/2L2
Lq = Ls + 3/2L0 - 3/2L2

Is it connected with the rotor type (salient-pole or round) ?
Why PSIM never indicate bibliography references ?
Thanks you,
Sophia