Steinitz classes of central simple algebras
A QTAG-module is an -module, where is a limit ordinal, if is totally projective for every ordinal . In the present paper -modules are studied with the help of -pure submodules, -basic submodules, and -large submodules. It is found that an -closed -module is an -injective. For any ordinal we prove that an -large submodule of an -module is summable if and only if is summable.