def pacstr(idpac):
    """Return correspond methods string."""
    if idpac[0] == 1:
        method = 'Mean Vector Length (MVL, Canolty et al. 2006)'
    elif idpac[0] == 2:
        method = 'Kullback-Leiber Distance (KLD, Tort et al. 2010)'
    elif idpac[0] == 3:
        method = 'Heights ratio (HR, Lakatos et al. 2005)'
    elif idpac[0] == 4:
        method = 'ndPac (Ozkurt et al. 2012)'
    elif idpac[0] == 5:
        method = 'Phase-Synchrony (Cohen et al. 2008; Penny et al. 2008)'
    elif idpac[0] == 6:
        method = 'Gaussian Copula PAC (Ince et al. 2017)'
    else:
        raise ValueError('No corresponding pac method.')
    if idpac[1] == 0:
        suro = 'No surrogates'
    elif idpac[1] == 1:
        suro = 'Permute phase across trials (Tort et al. 2010)'
    elif idpac[1] == 2:
        suro = 'Swap amplitude time blocks (Bahramisharif et al. 2013)'
    elif idpac[1] == 3:
        suro = 'Time lag (Canolty et al. 2006)'
    else:
        raise ValueError('No corresponding surrogate method.')
    if idpac[2] == 0:
        norm = 'No normalization'
    elif idpac[2] == 1:
        norm = 'Substract the mean of surrogates'
    elif idpac[2] == 2:
        norm = 'Divide by the mean of surrogates'
    elif idpac[2] == 3:
        norm = 'Substract then divide by the mean of surrogates'
    elif idpac[2] == 4:
        norm = ('Substract the mean and divide by the deviation of the ' +
            'surrogates')
    else:
        raise ValueError('No corresponding normalization method.')
    return method, suro, norm
