This paper discusses about quasi linear spaces in general and on section 3, it explicitly discusses about quasi linear inner product spaces with few good examples in 3.1 and about quasi Hilbert spaces in 3.2.
Dear @Raheam, here is the link to the 960 articles on quasi Hilbert space. It is Research gate publication database! Hope it will be helpful! I was looking in MIT data base with the same search parameters, but most of the papers were not available!
See Section 3.1, starting on page 20, on Hilbert bases. A nice example of a quasi-Hilbert element of the triangular faces of a cut cone is given in Fig. 3.1, page 21.
Quasi-Hilbert modules are introduced in
Thu Hoai, Le, Holomorphic structures and corresponding explicit orthogonal function systems in 3D and 4D, Ph.D. thesis, Technische Universitaet Bergakademie Freiberg, 2014: