An agent for treating keratin-containing fibers, in particular human hair, containing - at least one first fixative anionic copolymer comprising at least one structural unit of the formula and at least one structural unit of the formula and at least one structural unit of the formula where R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or a methyl group, R 3 represents a (C 1 to C 20) alkyl group, a (C 2 to C 6) hydroxyalkyl group or a *-(CH 2 CH 2 O) n -(C 1 to C 20) alkyl group, where n = 1 to 30, R 4 and R 5 represent a hydrogen atom, or one of the two functional groups represents a hydrogen atom and the other represents a methyl group, and - at least one second crosslinked anionic copolymer comprising at least one crosslinking polysiloxane structural unit of the formula and at least one structural unit of the formula and at least one structural unit of the formula in a cosmetically acceptable carrier, where R 6 is a hydrogen atom or a methyl group, R 7 represents a linear or branched (C 1 to C 20) alkyl group, a linear or branched (C 2 to C 20) acyl group, a (C 2 to C 6) hydroxyalkyl group or a *-(CH 2 CH 2 O) n -(C 1 to C 20) alkyl group, where n = 1 to 30, G is a direct bond or a carbonyl group, R 8 and R 9 represent a hydrogen atom, or one of the two functional groups represents a hydrogen atom and the other represents a methyl group, R 11 represents a hydrogen atom or a methyl group, R 10, R 12 and R 13 represent, independently of one another, a monovalent, Si-C-bonded, optionally substituted hydrocarbon group having from 1 to 18 carbon atoms (in particular methyl or phenyl) or a (C 1 to C 18) alkoxy group (in particular methoxy or ethoxy), m represents an integer of from 1 to 3, p represents an integer of from 10 to 1000, and X represents a direct bond or any molecular fragment. - at least one first fixative anionic copolymer comprising at least one structural unit of the formula and at least one structural unit of the formula and at least one structural unit of the formula where R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or a methyl group, R 3 represents a (C 1 to C 20) alkyl group, a (C 2 to C 6) hydroxyalkyl group or a *-(CH 2 CH 2 O) n -(C 1 to C 20) alkyl group, where n = 1 to 30, R 4 and R 5 represent a hydrogen atom, or one of the two functional groups represents a hydrogen atom and the other represents a methyl group, and R 1 represents a hydrogen atom or a methyl group, R 2 represents a hydrogen atom or a methyl group, R 3 represents a (C 1 to C 20) alkyl group, a (C 2 to C 6) hydroxyalkyl group or a *-(CH 2 CH 2 O) n -(C 1 to C 20) alkyl group, where n = 1 to 30, R 4 and R 5 represent a hydrogen atom, or one of the two functional groups represents a hydrogen atom and the other represents a methyl group, - at least one second crosslinked anionic copolymer comprising at least one crosslinking polysiloxane structural unit of the formula and at least one structural unit of the formula and at least one structural unit of the formula in a cosmetically acceptable carrier, where R 6 is a hydrogen atom or a methyl group, R 7 represents a linear or branched (C 1 to C 20) alkyl group, a linear or branched (C 2 to C 20) acyl group, a (C 2 to C 6) hydroxyalkyl group or a *-(CH 2 CH 2 O) n -(C 1 to C 20) alkyl group, where n = 1 to 30, G is a direct bond or a carbonyl group, R 8 and R 9 represent a hydrogen atom, or one of the two functional groups represents a hydrogen atom and the other represents a methyl group, R 11 represents a hydrogen atom or a methyl group, R 10, R 12 and R 13 represent, independently of one another, a monovalent, Si-C-bonded, optionally substituted hydrocarbon group having from 1 to 18 carbon atoms (in particular methyl or phenyl) or a (C 1 to C 18) alkoxy group (in particular methoxy or ethoxy), m represents an integer of from 1 to 3, p represents an integer of from 10 to 1000, and X represents a direct bond or any molecular fragment. R 6 is a hydrogen atom or a methyl group, R 7 represents a linear or branched (C 1 to C 20) alkyl group, a linear or branched (C 2 to C 20) acyl group, a (C 2 to C 6) hydroxyalkyl group or a *-(CH 2 CH 2 O) n -(C 1 to C 20) alkyl group, where n = 1 to 30, G is a direct bond or a carbonyl group, R 8 and R 9 represent a hydrogen atom, or one of the two functional groups represents a hydrogen atom and the other represents a methyl group, R 11 represents a hydrogen atom or a methyl group, R 10, R 12 and R 13 represent, independently of one another, a monovalent, Si-C-bonded, optionally substituted hydrocarbon group having from 1 to 18 carbon atoms (in particular methyl or phenyl) or a (C 1 to C 18) alkoxy group (in particular methoxy or ethoxy), m represents an integer of from 1 to 3, p represents an integer of from 10 to 1000, and X represents a direct bond or any molecular fragment.