| single- and multidrug resistance mutations to reverse transcriptase and protease inhibitors: human immunodeficiency virus type 1-infected patients from two geographical areas in spain. spanish groups for antiretroviral resistance studies. | to describe the prevalence of genotypic resistance mutations, including single and multidrug resistance (mdr) to reverse transcriptase (rt) and protease (pr) inhibitors in treated and untreated patients from two geographical areas in spain (madrid and galicia). | 2000 | 10881995 |